This concept, limited to cards that are in your deck, is unfortunately exploitable. Someone could adjust his deck such this this card would only draw ones that work exceptionally well together, probably by filling the Common choices with keyword-less cards. Not that someone would necessarily design a deck around a single card, but the possibility remains. (There is, after all, a reason that Dragon egg draws from the total pool of Dragon cards and not simply the ones (or one) in your deck.)
When you say token keywords, do you mean any keyword that can accumulate tokens or only those three (or fewer) keywords selected for that deck? I would hope it's not the latter, or else exploitation would be very easy. In either case, it needs clarification.