easy fix is you just use the ESEA playoff veto system, you both get to not play something you dont want to play and you both get to pick something you do want to play, its a simple 5 minute solution to all this.
I've been doing this with most of my scrim opponents lately and its worked out great and everyone was happy to cooperate :)
EDIT: here you go, save the copy pasta and message your opponents before the game!
The map pool is: cp_sunshine, cp_metalworks, cp_granary_pro_rc8, koth_product_rc8, cp_process_final, cp_gullywash_final1, cp_snakewater_final1, cp_badlands, cp_propaganda_b13
The high seed decides which team is Team A and which team is Team B.
1) Team A remove a map
2) Team B remove a map
3) Team A pick the first map of the best of three
4) Team B pick the second map of the best of three
5) Team A remove a map
6) Team B remove a map
7) Team A remove a map
(?) Team B remove a map
9) The final remaining map will be the third, if required, map of the best of three.