TexasIndian wrote
Should these be assigned to 2Ghz? 5Ghz? 5Ghz-2 Gaming?
(all 6 "With Ads" but Amazon say they can remove them to "Without Ads" after purchase/$15@)
@TexasIndian
It doesn't really matter. Although in SOME games, REAL TIME type, it could.
Many games you aren't really connected to the Internet to play them, however some are (like you mentioned). The "shoot 'em ups" usually need the quickest speeds (of the ISP download) and fast response times. Others, not so much.
Almost ALL could be on any SSID. The problem you could hit is 6 tablets vieing for Internet usage at the same time. Only way to know, try it and see who complains 
QoS by device could help you, but if you have 100Mbps Internet service, it might be more than enough.
My wife will play many game on her iPad. She'll buy the add-free deal for $4 or less occasionally. Not sure what requires $15 to remove ads, and it is usually done in the game, not Amazon?
I did find this though, https://www.laptopmag.com/articles/turn-off-ads-amazon-fire-tablets, but it isn't too clear? It seems you can save $15 by allowing ads NOT to appear. However it seems the info there will turn the ads off if you allowed them to be shown?