Game is hard

[Kalenden]

Hello, I'm playing the standard AP campaign with Crossworlds ( March of the orcs it is called I think ) and I'm finding the game rather difficult.

I'm a Paladin, lvl 5, developing my character trying to reach resurrection first. I've cleared out the first island (completely), have got 800 leadership ( 12 Royal Snakes, 10 Ancient Bears, 12+- Archers, 8 Inquisitors and 16 priests ) and I'm finding the second island ( Scarlet Wind I think ) too hard.

I basically tried my standard tactic of first clearing all the reachable weak units from the map and looting a little bit (I'd rather not kite) and then pass on to the stronger ones. Problem is, the stronger ones are a lot stronger. I'm trying to do this without incurring any losses, but if I want to fight new units I will incur a lot of losses since they have a lot more units than me. I am keeping off from buying any items to help me (saving for something that gives +10 mind runes after 50 victories) but that shouldn't be a problem.

So, any advice on how to deal with the situation? Also, any advice on how to develop my Paladin is also appreciated.