[Baalz]

Caveate: I haven't played Tir yet. That said, I can offer some suggestions as to some specific questions raised. Tir, like Eriu seems likely to do very well with a heavy forging focus. Sidhe raiders obviously are exactly the same, but cheap items can go a long way towards overcoming some of the other weaknesses.

A couple indie commanders with ice pebble staffs will go a very long way towards compensating for your low damage output and will quite vex the guy who managed lightning resistant troops. Generally though lightning casters + soothing storm will bring all the damage you need.

Sidhe champions have an 18 precision once you cast eagle eyes. Bows of war and piercers can be pretty nasty when you field double digits of them, particularly on stealthy guys.

Enemy SCs shouldn't be a problem. Anybody not lightning/frost immune is trivial to bring down, and hero blades are an obvious default answer to anybody that doesn't have a more specific weakness.