Pat, the T210 issue date is not just based on team affiliations. Sometimes I think you have me on your ignored list.

Look at the newspaper clippings you yourself posted, all but one point to a 1910 release date and in that other you hyper-focus on one verb tense in one sentence. That’s it, that is all you have shown, and I’ll get back to that in a bit.
1. Do you agree that the Old Mill Cabinets came after the T210s? As I stated, one team in particular moved from Portsmouth to Petersburg in July 1910, and the cabinets show Petersburg while the cards show Portsmouth. Is it not logical to conclude that the cards would have been corrected if produced after the cabinets, and because they were not, the cards came first?
2. A December 1910 article that you posted makes reference to the cabinets being made available a second time, having been released previously “some time ago”. This points to the cabinets being available and enjoyed in 1910, and if the T210 cards preceded the cabinets, wouldn’t the same hold true–1910?
The player referenced in the article on which you rely (post #1) is Sharp, who appears on Goldsboro in Series 7 of the T210 set. We know that Series 7 depicted only East Carolina Leaguers. We also know that the cabinets show players from three different leagues, which correspond to Series 2, 5 and 7 of T210. Since the cabinets for players from these leagues are known to have been available “some time ago” in 1910, and the cards from these leagues would have come before the cabinets, then it stands to reason that Mr. Sharp’s Series 7 card was available in 1910. So the one player whose card you question as to date seems pretty clearly attributed to 1910. Or am I missing something? Add to this that there are clippings announcing in March 1910 that the cards were coming, and others from April and June discussing the cards, and I still believe this is evidence of a 1910 release.
However, the best point you made was about the Shelbyville to Maysville team move late in the 1910 season. That indicates a later release for the Series 6 Blue Grass league, although it is not clear that extends it into 1911.
I had assumed the T210s were all issued near the same time, based mostly on my observation of the Series 2, 5 and & 7 series I just referenced. In addition to their being featured in the H801-7 cabinet checklist, Series 2, 5 and 7 also share many photos with the T209-2 Contentnea set from 1910. Why skip number those series unless the others were already produced, although I guess they could have been intended for production and just got a late start. As for series 8, it uses several photos from the T211 set that has also been dated to 1910, so that too fits nicely with a 1910 release date. There is more to be investigated, for sure, but IMHO 1910 looks far more likely right now than 1911 for the Old Mill T210s, and not just because of player-team combinations shown on the cards.