With new special abilities we can have builds consisting only of one weapon type that are extremely effective because of special abilities.
In this build overcharged engineer mods were applied to all and with special abilities: Huge with Incendiary Rounds against shields, 1 medium with Corrosive Shell to soften enemy hull and 3 medium with thermal shock for transferring little heat to enemy and besides it has nice lightning effect. Only drawback for this build is limited ammo - you will run out of ammo eventually, but you can always craft ammo and even increase damage done.
So full cannon, fragment, multi-cannon loadouts now can work very effectively.
(c) Frontier