In the endgame (most of the time) I have only characters with two handed weapons in the front line, using your example it would look something like this:
P is for a man armed with a pole arm and with perks that promotes inflicting injuries.
This is the setup I run against most foes and on most terrains.
if I’m fighting goblins, armies of orc young or in hilly terrain I usually have a set up like this:
Where the men with shields have throwing weapons and spears, that way you can counter the ranged superiority of the goblins, and open up the front lines for an assault, use the throwing weapons to take out goblins with spearwall or nets while the archers take out their archers e.t.c.
In hilly terrain the extra adaptability of having men with throwing weapons makes up for the lower damage, you can hit foes you can’t walk up to and hit many times.
And the spearmen with shields really help vs armies with a lot of orc young or orc berserkers, since the charge can be deflected most of the time, (in the set up I displayed earlier there are only two spots where a charge can end without hitting a spearwall, so only two of your men with great weapons can be stunned as long as your spearmen have high enough melee attack).
Running this style of company relies on having a lot of heavy armors and without a decent supply of scale mails or heavier armor it’s quite susceptible to be overrun by foes.
I find that after the talents and perks update a well built character with coat of scale or coat of plate and a great weapon can easily go toe-to-toe with an orc warrior, and often times take out two or more on their own.
There is one last variation I run against skeletons which is:
P O P
Early game I find that it’s mostly about making the best of your situation and your setup should reflect that, but I have over several campaigns aimed towards a setup as I have laid out in here and it has worked well on the middle difficulty (not sure what it is called right now).
(Imagine the second rank as centered)