Hey I have two suggestion :
1/ An option to skip first character turn of all the party members at once. I often wait for all the enemy force to make their move and I use the second character turn to act (position and attack), and I must pass every mercs one by one. it depend on enemy and mission type also but it can be usefull.
2/ An option to select who’s mercs play or just stand inactive. Often in the end of the battle, I must chase fleeing rooted troops or archer et I only want to send a group of 2 or 3 mercs to finish the job. If we can make all other mercs in wait stance it will be great. otherwise it’s just pass, pass, pass, pass …10 times per round till I catch them all.