I've run a few simulations on TM/TM opens, against Market/Silver and Wharf/Silver. It wins about 33% of the time against Wharf and about 50% againt Market, although those are not entirely optimised. Testing it with the TM's being forced to collide turn 3 (with 3 coppers) against Wharf/Silver, the win rate becomes about 80% - lower than I thought it would be, actually. Note I did let it buy Wharves since they're on the board.
So... TM/TM is not really a guaranteed win. Wharf BM is strong, but there's much better engines, so even a turn 3 collision can be beaten by either a good player, or later luck.