Advice for impossible Paladin?

[hyn]

This is my second try at impossible Paladin. I know I'm supposed to get the Resurrection skill asap, but I can't even get there.

The first island is easy but from the second island it starts to get ridiculously hard. By then time I get to the third island (lv 9, 10 ish) almost all enemies are Lethal, and no matter what I do I lose stacks of units every single battle. Also, how are you supposed to beat the catacomb boss (machine thing)? The repair bots have ridiculous physical resistance, mobility and range.
I'm not even talking about a no loss challenge.

Please give me some advice.

My main units are:
Polar bears (I try to keep them alive but against 100+ stacks of pirates and other crap, there's no chance)
Inquisiitors
Priests
Seadogs
Bowmen