Having trouble with Warrior on Impossible

[Evermind]

This is my first play through, need some tips...

I'm about 80-90% through level 8, almost level 9, and I have already cleared all but just a couple units in Darion. Done all of the quests, except for one which is way too hard (Emenem in the cemetary)....

I have about 77,000 gold right now, which doesn't appear to be much since I know I could deplete that very easily. Especially considering the challenge rating of the enemies on the Western and Eastern islands (Strong and higher to me).

I've already bought a boat and picked up most of the items that I could around the Western islands without getting into any fights. Going to do that also for the Eastern islands now too, but I don't see how that is going to get me past the challenging enemy units that I'm going to have to face.

I'm running a Warrior with just about 3100 leadership, 6 Attack, 7 Defense, 2 int and using Decaying Zombies, Skeletal Archers, Cursed Ghosts, Royal Snakes and Polar Bears.

Only notable skills are Level 2 Dark Commander and Level 2 Distortion magic. I'm using the Rina zombie lady as a wife with +10% combat experience artifact. My hero basically only has the starting artifacts that you get from the tutorial, with the exception of a +5 mana ring.

I haven't seen any particularly good items to invest in yet, most everything is Int or mana, which as a warrior I'm not too excited about.

The only items I can think of are:
Helmet (I already have a helmet with simply +1 defense though)
10,000 gold
+1 Defense
+200 Leadership

Two Belts (one for me and the wife)
6,000 gold (total 12,000 gold)
+2 Defense each (Total +4 defense)

Painting
16,000 gold
-3 Attack to Enemies

So, for 38,000 gold I can get +200 leadership, +4 defense, -3 to Enemy Attack.

I guess my question is, are these items worth investing in for the money? I have a feeling that I'm going to taking heavy troop losses on the Islands and may need the money for buying units and it doesn't seem like to me that these items are going are going to minimize those losses. Am I wrong? Should I buy them?

Any help, insight, or ideas would be helpful... Thanks!