It's been suggested to me that infinity gems are team tactics cards. Since infinity gems aren't mentioned in the Building A Roster section on page 9 of the online rulebook, or anywhere else I could find in that document, except their own section in the appendices, and look pretty much identical to team tactics cards, I'm having a difficult time refuting that assertion. Can anyone cite a portion of the rulebook that defines infinity gems and team tactics cards as different or otherwise resolves this issue?