>>7450262The cannons pretty much only fit MF34 in those two slots cut out for it, so you're mostly getting them for compatibility with Diabattles V2.
The blue cannons are interesting because they use the same exact shade as the red/blue "hero" Diabattles. As for the the silver-painted cannons, there are better sources, like their own Cosmos Battles, Diamond Cyclone's (new KO maker) Cosmos Battles or even Takara's official version.