Stuck on last bits of Scarlet Wind

[BT1]

I'm playing mage on hard mode. I'd think i was good with games in general but i may have overreached myself this time.

Ive unlocked scarlet wind and bola. Bola is too hard but even so ive taken many of the banner flags (without any battles).

Ive got 1270 leadership. Im down to 5 enemies on scarlet wind, one of whom is invincible, two are lethal and one is very strong. One more which is slightly weaker but im ignoring since it won't change my immediate situation.

The very strong one is guarding a map. Also it this is the only one with the possibility of winning, but its stacks are so huge

Could someone please give me some advice to help me for this early part of the game? any "dirty" tricks i could use to at least get me through this part of the game?