600 points of guard for the schools league

[dark1thought]

For the Schools League sometime next year.
My first list was as follows:

Company Command Squad, 3 Grenade Launchers, Vox Caster
Veteran Squad, 3 Meltas
Platoon Command Squad, 4 Flamers
Infantry Squad, Autocannon, Grenade Launcher, Vox Caster
Infantry Squad, Autocannon, Grenade Launcher
Infantry Squad, Autocannon, Grenade Launcher
Vendetta
Aegis Defense Line

I then noticed a problem with the list. At the schools league, in the two qualifying rounds, we often have to play on very small table (2' x 4')
So that may cause some severe problems for the flyer, as it would constantly fly off the table. I could also go into hover mode, but that kinda ruins the point of taking the flyer.

So I thought of making some amendments to the list.
What do you guys think of replacing the vendetta with a chimera for the vets, and also adding in a griffon heavy mortar. I could then remove all the grenade launchers and a flamer from the PCS, and then give the CCS 3 plasma guns to make the list as follows:

Company Command Squad, 3 Plasma Guns, Vox Caster
Veteran Squad, 3 Meltas, Chimera
Platoon Command Squad, 3 Flamers
Infantry Squad, Autocannon, Vox Caster
Infantry Squad, Autocannon
Infantry Squad, Autocannon
Griffon Heavy Mortar
Aegis Defense Line

Do think this is a good change to make? Would you suggest something different?

Thanks :D

[velox atrum]

with the new lower gets hot rule (only 1's not 1's and 2's )Plasma is a bit more usable. I give my Vets 3 Plasma and a Las Cannon so the BS-4 makes lascannon a vehicle sniper and its always nice tagging 3 or 4 Meq's at 24".

With Carapace the Plasma is even less problematic (its costly but means when those meq's fire back you get a save)