Using 2 3way switches in a single pole double gang box

Not sure what you mean by "The 3 way switches have a "neutral wire in, a hot wire in and 2 traveler wires coming out of them". Then you said, "all the whites are connected". So that needs clarification.

There are several ways of connecting 3 way switches. my preferred way is power in to the "first" switch, 14/3 to the "second" switch, then from there to the fixtures. No code taping required, conceptually the simplest. I sounds like yours "might" be wired that way, but again, need clarification. If it is wired that way, the neutral (white) from your smart switches just need to be tied in with the other whites already there. But double check.

I know this isn't a complete answer, but I don't have enough brownie points to "comment" yet. Sorry.