Why should he wait? A revised set axis or allied force will only have a single light walker anyway.
If you want a similar force, I'd go with:
- Operation Zverograd (walker and hero)
- Fakyeli (close combat fast squad that can deal with walkers)
- Frontoviki (good anti-infantry squad)
Then it gets a bit tricky. You should get a 3rd squad, but your options are the Medvedi command squad, which would be a bit unfair to the opponent or the Chinese Volunteers. I'd go with the Chinese Volunteers, even if you don't use the chopper because you won't have enough AP. You could alternate between using the chopper and using the Babushka walker, putting Koshka instead with the Fakyeli (should be quite deadly).
EDIT: Ture, if you're fighting an allied revised set army, it would be unfair to take a chopper. Against the axis it would be all right, with Lara and the Flaks being among the best units in the game to bring down aicraft. Ohotniki isn't out yet, or it would be a good option for the 3rd squad. Either it or a Commissar squad.