Well my take on it wasn't the Shas'o, but the Shas'el. Being 25 points cheaper, I can give him a twinlined weapon cheaper than the BS 5 upgrade would be (at 25 points). And Twinlined BS 4 is better than a single shot BS 5 anyway. Plus, with three Harwired options, he's got them to spare unless I'm getting silly with the points. As an example:
Shas'el Shas'vre shas'vre
Twinlined Fusion Twinlinked Fusion Fusion Gun
Plasma Plasma Plasma
Hard Multitracker Hard Multitracker Multitracker
Hard Target Lock Hard Target Lock
Hard Drone Ctrlr
Traditional wisdom would seem to be take a Shas'o instead of a Shas'el, but like I said this is a cheaper option. It also gives one of the Shas'vre an increased chance to hit with that single shot weapon-of-goodness. The BIG thing different is usually I'd be taking a drone controller on that first Shas'vre, and a shield generator on the Shas'el. So it's a trade off of survivability for firepower.
Which is the real question here, now that I'm sure it's legal. Exactly HOW survivable do they need to be? And how much difference does the extra firepower make?
I suppose playtesting is in order.