Again, how polite. ^_^
In FACTIONS.XML, look for <Land_Skirmish_Unit_Cap_By_Player_Count>.
There's a separate section for the Rebels and the Empire.
You'll see three sets of two numbers divided by commas.
Change the numbers after the commas to something higher than 10.
I don't mind explaining it, it's just that I haven't personally DONE it, so I don't vouch for the method.