Well...that's sorta what the Squid does right now- it's a fast, fragile ship that can move in, shoot up an enemy, then escape before the enemy can respond. It's even got a rear-facing gun for the old parting shot. The Pyramidion also works somewhat like that, in that it's designed to fly straight toward the enemy, guns blazing. (and then hit them head-on)
Coming up with a new ship is hard, because you basically need to design a whole new niche that's not already being filled by one of the current ships. The best I could come up with is a true blocking ship- one that's nigh-invulnerable from a single side, but all its guns face the other way. For a brawler, you'd use your shield as cover to close, then flip around and start blasting. For a sniper, you'd be safe from an enemy ship ambushing you on your blind side. Putting the shield on front is too obvious- what about the right- or left-side? Then you're not just flying straight at the enemy like a Pyra; you've got to circle a little bit to close- very different tactics.
Its use for teamwork is obvious- ally having trouble? Get in between them and the enemy's guns to provide them some time to repair. It could also provide a big, juicy distraction while an ally's Mercuries do their work, or allow a fragile gunboat (Spire/Mobula) the protection it needs to close into range.
It could have good acceleration, but perhaps be a little slow to turn (unless you use a Phoenix Claw). I'm thinking...four light guns, or one two light and one heavy; they'd face the three directions the shield doesn't cover. If you put the shield on the right side of the ship, then the dual light guns (or single heavy) would face forward, with one light gun facing to the left and rear.
Edit: I call it...the Paladin.