The warrior "martial skill" traits got nerfed (they used to be +2) and for a mere +1 it's not worth going nuts to maximize every possible possible card to work with them, imho. Or spending power tokens on the slot unless you *really* have nothing better to use them on. For one thing, you'd be really sorry when you have 90% penetrating stuff and come up against enemies with immunities, like skeletons. That being said, having a fair number of penetrating cards is pretty handy well through the mid-campaign at least, and for that the Penetrating martial skill card is the best use of the slot. Later you can make sure your wizard has a good mix of armor stripping cards, those are a little hard to fit in early on. There are some dungeons where it is a good idea to tweak your gear beforehand - I've been lucky so far this runthrough carrying a mix of stuff and only died a couple times (with a fair few more that were CLOSE calls). I haven't gotten to those damn monkeys yet though :p
MP - make sure you have some way to deal with being on lava and out of movement/encumbered - a decent number of team move cards, the terrain clearing/changing cards, or heck even armor and healing, whatever. Some ways to remove bad status effects like encumbrance is nice too. A lot of guys have from some to a lot of encumbrance adding gear like ice wands that will stop you dead in your tracks, then they pop lava or spikes or acid underneath - I've seen that called a Control Wizard. For warriors I like a human or dwarf with decent armor and a lot of the combo movement/attack cards - that's called a Step Warrior. And then the cleric I give mainly stuff to buff the warrior and do a BIT of healing and a BIT of fighting - especially a few "get away from me" bash cards. The main buff I liked was "Martyr" - draw a card when you take damage, that helps keep the warrior moving forward or drawing more attack cards when he's toe-to-toe. With a few odd "frenzy" type cards to boost his damage a bit. If you go with 2 warriors/1 cleric the "mass frenzy" is really niiiiice too.
Warning - I'm only mediocre at this game, so take it all with a grain of salt
I did OK with that combo, but I never made it anywhere near the top MP levels, I peaked at about 1050-1100 rating. I was mostly interested in getting a couple of chests in a reasonable time instead of getting to the top of the rankings so I didn't have a good way of dealing with some threats, just hope to get lucky - but you can't guard against *everything* and there's a big random factor anyway, so you gotta figure out a decent tradeoff...