Um, Kahuna, I don't think a factor of two difference against 4 hull types, even if they are very common, is quite enough compensation for half vs everything else. I don't think snipers are bad, per say, just almost completely worse than sentinals.
I just realized that majority of people think like this. A little bit of everything is always better than a lot of few things (specializing in something). This is also why Left 4 Dead is mostly unplayable on the highest difficulty level. The only/best way to survive is to work together and move as a team. Kinda like a SWAT team. Everyone moves forward in a line next to a wall and everyone covers 1 direction. This way everyone covers each other and every direction is covered. When I try to explain that.. they say "everyone cover every direction!". Then everyone except me ends up running around the map alone like Somalis with AKs. I call people like that "bot brains".
As I said "Snipers will destroy Fighters and Bombers and thus protect Bombers and Missile Frigates". Snipers wont destroy Missile Frigates but they don't need to. Bombers are good at doing that. Sentinels aren't bad at all. They're good.
When I have Snipers as a bonus ship..
2 ship types (Snipers and Missile Frigates) destroy Lights (Fighters)
1 ship type (Bombers) destroys big guys and Artillery (Missile Frigates). I unlock MarkII Bombers so I kinda have 2 ship types destroying big guys and Artillery.
2 ship types (Fighters and Snipers) destroy Polycrystals (Bombers)
2 ship "types" (MarkI and II Bombers) protect Fighters by destroying Artillery (Missile Frigates)
2 ship types (Fighters and Snipers) protect Artillery (Missile Frigates) by destroying Polycrystals (Bombers)
2 ship types (Missile Frigates and Snipers) protect Bombers by destoying Lights (Fighters)
Now my fleet is balanced and everything is covered.
"Oh by Sentinels cover and destroy EVERYTHING!"
Yes, but no.