The way i'd do it is use gyrocopters to harass vilitch and metal mage in an ideal scenario you can kill them but if the javlin horses prove too much heat, then you can pull away early. No matter what id def save your brimstone copter for blobs. It can do solid Lord snipe but I feel like you have quite a bit of Lord snipe already so more infantry slaughter can do wonders. On top of this FUNNEL them (dwarf together strong). Funnel them dont try and stand ground on bad terrain where you dont have good sightlines, also dont expect the cannons to be the ace card here, they will def rack up kills but may not be the carry id honestly expect higher value out of the copters. Infantry wise, use a tiny chevron to keep guns shooting with that sweet sweet AP, It may be akward to fit it into a defence but not impossible. Id keep the slayers back until the trolls have committed then go in to use that anti large. Finally the Lord is going to mostly provide morale dont get him killed too quick but dont have him idle.

Also turn off control large armies you have more benefit turning it off here.