OK Zan, I did some additional checking, and I think I see what the issue/question is. And I don't know if there is a right or wrong answer after all.
https://oldcardboard.com/r/r314/r314.asp?cardsetID=872
The Old Cardboard site also lists a description of the various Goudey wide pen Types. They say the Type 5 cards do include some Detroit players, as well as all the International League players that the SCD catalogs says make up the Type 5 cards alone. Now the SCD catalogs say the Type 4 and Type 5 cards both have a similar creamy colored stock that those two Types alone use, and Types 1-3 use a different, more white stock. Which is true. The Old Cardboard site makes no direct mention of the creamy colored paper/cardboard stock differences, and specifically which Type(s) it relates to, but instead just mentions that the Type 1-4 cards have a glossy front surface finish, while the Type 5 cards have more of a matte front surface finish, which also appears to be true. The SCD catalogs show all five Types as being Goudey cards, whereas the Old Cardboard site shows Types 1-3 definitely as Goudey cards, but then shows Type 4 and 5 as possibly not being Goudey cards, but World Wide Gum cards instead, a Canadian issue. But the Old Cardboard site puts questions marks after the WWG designations, so they obviously aren't certain either. What is also interesting is that the SCD catalogs show the Type 4 wide pen card set as having 36 cards of 34 different major league players listed in it (two versions each for Pete Fox and Schoolboy Rowe), while the Type 5 International League cards have exactly 39 different players/managers/trainers that make it up. However, in obvious contrast/contradiction, the Old Cardboard site shows there are only 26 cards that make up the Type 4 set, while they list the Type 5 set as having 47+ cards in it. Why the big discrepancy in the number of cards in each of the two Type sets between SCD and OBC, and especially why does the OBC list the Type 5 set as 47+ cards, meaning they don't really know how many cards are in the set? And to make things even more confusing, the OBC site doesn't list what cards make up the Type 4 and Type 5 checklists. So that is no help. But what it does seem to do is indicate that maybe the OBC site is suggesting that they completely removed some of the cards off the Type 4 checklist entirely, and switched them over to the Type 5 checklist. So does that mean if you want to consider there is a Type 5 Greenberg card after all, that also means there is no longer a Type 4 Greenberg card then? And if not, then what cards did the OBC site take from the Type 4 checklist and apparently add onto the Type 5 checklist after all then?
Then in looking at other sites, like the Pre-War Cards site, for info on the Goudey wide pen sets, they also confirm the five different Types, and that the Type 5 cards are to also only be Canadian, International League players, just like the SCD catalogs do. They also agree with the SCD catalogs that the Type 4 set is made up of 36 cards, while the Type 5 set is made up of 39 cards. The Pre-War Cards site also speculates about the printing of some of those wide pen cards by the World Wide Gum company, and goes even further to speculate that the Type 4 and Type 5 cards may therefore be incorrectly classified as R314 cards to begin with, and should be considered as part of a separate V352 set, as identified by Jefferson Burdick in his American Card Catalog.
https://prewarcards.com/2016/10/04/1...premiums-sets/
https://prewarcards.com/2016/09/07/1...and-checklist/
You had made a reference to Burdick earlier as well. But if the Type 4 and 5 cards really should be in a separate Canadian issued set per Burdick, then there is no Type 5 (or Type 4 for that matter) Goudey wide pen Greenberg card at all, just a V352 version. But if you choose to ignore Burdick's own classification and list the creamy colored wide pen cards as R314 Goudeys, I believe you have to then follow the SCD catalogs as the most authoritative source, and only consider the International League Canadian players as Type 5 cards, and the major league players as only Type 4 cards. Now both the Type 4 and Type 5 cards have the same creamy colored paper/cardboard they were printed on, but then there is apparently another difference in that all the International League player cards had more of a matte front surface finish, while some of the major league player (Detroit) cards can apparently be found with both a glossy and matte front surface finish? If that is the case, that may be the result of having a switch in the stock or printing process at some point when printing the major league player cards. Regardless, I think you still have to recognize that the International League Canadian players are to be considered a separate set/Type, as the SCD catalogs have put forth, and that if there are two different versions of a Greenberg card, a glossy and matte version, then those are Type 4 variations, not a Type 4 and separate Type 5 card.
And the same would hold true I believe if you consider the Type 4 and Type 5 cards are actually part of a V352 set. They would all be the creamy colored paper/cardboard material, but possibly a matte and glossy version for at least some of the major league players.
And in doing a quick look at pop reports, I noticed that neither PSA nor SGC has any Type 5 graded Greenberg cards. In fact, the only PSA graded Type 5 cards are all just of International League players. Oddly though, SGC does have some major league player's wide pens (both Detroit and other teams) labeled as "Canadian" instead of Type 4 or Type 5. I would guess these are all of the creamy colored Type 4. Now there were some other SGC graded Goudey wide pen cards labeled as Type 5, not many, and all but two of them were also of just International League players. However, one of those SGC graded cards labeled as a Type 5 was of Charlie Gehringer, from the Detroit Tigers, which would tend to prove the idea that there are Type 5 cards of Detroit players recognized after all. But then I looked and saw the other SGC graded card also labeled as a Goudey wide pen Type 5 card as well, of Jake Mooty. Thing is though, Mooty was just a very minor relief pitcher who did play some in the majors in 1936 and 1937, but he did so for Cincinnati, not Detroit. Also, though he did play some minor league stints in '36 and '37 as well, Mooty was in the AA and never played in the International League in his career. And lastly, Mooty never appeared on any of other the Type 1-4 Goudey wide pen card issues either, so why in the world would he suddenly have a Type 5 Goudey wide pen card......the answer is, he wouldn't! So, it is pretty clear that this SGC graded card is completely mislabeled as a Type 5 Goudey wide pen card, which makes me way more easily suspect the Type 5 labeled Gehringer card is likely in error as well.
If someone else wants to believe the OBC site, and the reference to a 2006 article as the source of their reference to Type 5 Goudey cards including some Detroit Tigers players, then why did the SCD catalogs prior to that article, and for at least a decade after it, continue to list the Type 5 cards as only including International League players? Bob Lemke and his staff would have most likely heard/seen/found something about this alleged difference in thinking, and vigorously investigated it. And the fact that they did not see fit to change their checklists and descriptions, nor even make mention of any potential issues or questions, to me is more than telling and compelling that there are no Type 5 Greenberg wide pen premiums. Maybe a glossy and matte version Type 4, or a glossy and matte version V352, but not a separate Type 5. But if some people still want to ignore the SCD Catalogs and their recognized authoritative history, along with the support from other like thinking sites, I guess they can call them Type 5s if that is what they really want to do. But it still goes against authoritative sources out there, and makes little logical sense on its own Good luck with your collecting.