They usually win on Haven but I dont think its their best map. They struggle sometimes on attack on that map. They play more confidently on Icebox imo.
Sen's strongest map depends on whos feeling it on the team. If SicK and Dapr's feeling it, Haven. If Shahz and Tenz feelin it, Icebox. If SicK and Tenz feelin it, Split.
That is actually probably their worst map other than Ascent, their best is Split and Breeze their haven and bind are good too and then their icebox and ascent are ok
Discord