Phaenur, thank you very much for your time and help, sir. It has been very useful.
I'm sorry for a little misunderstanding: I'm a Vaegir's vassal, but I don't use only Vaegir's troops. In fact, I only use their archers aiming (with low hopes) to theirs T7. As infantry I own few T4 and T5 Rhodoks aiming to some Condottieri. As cavalry I'm using mainly Swadians, aiming to barons.
The thing is that I tend to use the few infatry units I possess as a shield for the archers, not using any formations. Which would you say is the best way to manage a fight with these components? As said, I put the archers in the nearest (or higher) hill around, infatry in the middle and cavalry much forward. I take advantage of the AI tendency of make some troops to just following me endlessly, to kills some and split their army, and when the rest charges I wait them to get near my mounted troops and then order cavalry to charge as well. Infatry just stays in hold, but I don't even know if they'll be of any helps when I'll be fighting bigger armies and I'll actually really need to defend my line of ranged units. Do you recommend any formations in general?