After several tries at the mission, this was the most efficient configuration I got. Shouldn't be too expensive, and AFAIK doesn't use anything that isn't available at your stage of the game.

https://i.imgur.com/i3mwaAt.png

5x Chappy/Line-mon (assault)
2x Francoise (sniper)
1x Mine (Recon)
1x Pumpkin (control)
1x Marble (command)

How it works
Refer back to Juff's map here.

There are four enemy command tanks. Two Chateaus (the pink hairs) who move into the bottom left, one Seri (cybertank) in top right, one Himiko (blue hair two-square) in top.

Our deployment:

- Bottom left team's job is to destroy the Roast artillery in the bottom left, then find the Chateaus and snipe them. Interceptor keeps the other artillery tank from flattening us until this happens. Control tank has the added function of disabling enemy modules.

- Command tank stays in corner and doesn't do anything.

- Assault tanks sweep upwards along the path, killing everything along the way. Top priority is the two enemy command tanks, but take out targets of opportunity including the big Pegasus artillery as well if we can. Sniper is there as backup if someone's evasion gets really annoying.