you can fire all three lascannons if you stand still, thats the true advantage of that set up: Massive anti-tank Power
If you move 6" then only one cannon and all defensive weapons (meaning HBs)
I'd still recommend choosing all lascannons or HBs/Autocannon set ups but w/e you want
On a side note, If you want a fire base Snipers are better IMO:
12" more range
Pinning
Hits on +2
wounds on +4
The only disadvantage of snipers is you can't move and fire but you said you don't need them to move much...pinning has save my @s* many a times
