[Lazy_Perfectionist]

The following post is not based on any relevant experience, just extrapolations. Test it in SP before going MP.

Someone provided an interesting bit of advice for me on Shinuyama. The assassins are quite different, but there may be some relevance. (For me it was Mujinas with Skull Talisman, but Slayers are better equipped - no death magic available, though).

Your slayers are fairly inexpensive, and your fire gem income high. You may consider sending Slayers out to assassinate independent commanders. On average you'll face two commanders. Once those are dead, just send in a small force. The entire enemy force will route. I'm not certain what I'd do with the fire gems, maybe fire pearls or drakes?

You've got a 2 fire sacred mage for 130 gold. The research is a somewhat of an issue, but if I'm correctly remember +6 fire gem income, you can afford to spam some fire elementals to help with expansion.

So, one thing I would try in the beginning turns is recruiting the cheapest mages, and spending most of my gold on Salamanders (area attack 1, AP!) or Misbred. Assuming a 400 income base, 80 R...

I'd recruit two infantry, an Anathemant Salamander, and one Salamander taking up about 60 resources and 230 gold. I'd spend the rest on Misbred. They may be chaff without armor, but 6 prot isn't bad for EA, and it'll help prevent wastage of your infantry.