Ya in Chapter 11, I more or less had the same thing happen with Drake. Wanted to make sure I visited all of the houses, didn't want to run into the boss, went the long way, Drake was dragging everyone down and somebody got hit so I had to heal them and then I got bum rushed. They got to me too quickly so I couldn't keep pressing onwards because would have just triggered more units.
I can't remember, are their any flying units in the Elite group? If their are, switching them out for 5 movement units might work: you don't have to stop to fight the Elites that way, its still a group you want to avoid if possible, but you don't get tagged by fliers quickly and stuck fighting them until the other Elites catch up.
The changes I suggested to Andrei were less about straight up buffing him and more about trying to lower the chances of him getting screwed. It's a bit tricky to buff him without making Val obsolete, but then there are the problem of the other sword users you get pretty quickly after you get him back. Something I can spitball out about that is maybe give him even more Con? Out of all of those sword users he has the highest Con, but he's only beating Jace, Ordanze, and Laraya by 1. I actually ended up giving him a Body Ring before I promoted him. Perhaps just buff his Con up by 2 so he can use some decent swords without any speed penalties? That could work as his niche: doesn't have the greatest speed when compared to the others but he's not weighed down by most of the swords in the game?
Compared to other axe users: Kane would have the same amount of Con but is an all rounder who trades some skill for some defence and access to two weapons from the start. Vincent would be tied until promotion where he takes the advantage and has better strength, speed, and def on average. Hawke would have 1 less con until promotion but has better strength, speed. Marco still has a Con advantage along with strength and defence.
Another possibility would be to buff his unique sword a bit. Basically have it be "without his unique sword he's slightly worse but has access to ranged weaponry upon promotion when compared to other sword users, with his unique sword he's slightly better overall"? Gives a reason to use the weapon repairing staff as well.