Thanks for all the advice so far (and all the welcomes), I'll take it all on board, and will start looking at the TOC threads soon.

Papewaio's advice was particularly helpful what I have tended to do in my games before now (especially the VI ones I've played recently) is take a lot of ranged troops such as archers in my armies (sometimes as much as 4 or 5 regiments) in order to try and whittle the large Irish melee regiments down a bit (as well as their own missile troops such as Bonnachts and Kerns) before my spearmen and Huscarles engaged. I also found myself taking siege weaponry in standard armies as I felt their fear causing effect (and the thought of seeing several large rocks flying towards yer lines) would scare the enemy enough to cause their more undisciplined units (such as peasants) to run.

As far as the main campaign goes, I've tried the English several times and had the unfortunate problem of running out of heirs when I start going well (and even without a single battle). So, my most recent games have been with the slightly reduced capabilities of the VI campaign's armies, so maybe once I'm able to get a good start in the main campaign I might have some better luck