I think matlock always should be in 2 rows, so for example a matlock sam whit 90 men should maximum have 45 units in the first row if 2 dies it should maximum have 44 units in first row, like medival 2 has it. reason why, like it is now a matlock unit that has lost half its men still have have 75% fire power. and a matlock that has lost 30% still have full firepower strenght.
Second reason is that fire by ranks would be a skill to use.

Have a good day