4+/4++
Unless I am really missing something, the broadsides have no ++-save.
And with a "low" toughness that means they die way too fast to Instant Death.
The Commander gets T5, but if he joins the Broadsides he will get downgraded to T4. So the only benefit is 2+, which isn't needed if he stands behind the guys.
In my opinion that's extremely expensive for such a small benefit.
Two drones with 4++ could be used to tank a few shots.
Or do you plan to put the Commander in front and let him tank the shots with his huge amount of wounds?
And the following depends on the meta, but I would upgrade one "Target Lock"-Broadside to a character and give him Advanced Target System instead of "Target Lock".
Sniping away special units has never been easier

especially with both missile-weapons.
8 rockets:
2.67 precision strikes
1.33 hit
4 miss => reroll => 1.33 precision strike, 0.67 hit and 2 miss.
So with 8 rockets you will have 4 precision strikes, 2 normal hits and 2 misses. (2 are str7 and 2 str5)
That means a hiding Space Marine with an AP1/2-weapon (which would scare me) would get 3 wounds and that should be enough to get through his armour.
That brings us to:
Commander:
Command and Control
Multi-spectrum Sensor Suite
Puretide Engram Neurochip
2x Shield Drone
12x Fire Warrior with Pulse Rifle
2x Broadside Shas'ui
1x Early Warning Override
1x Target Lock
2x
TL High-Yield Missiles
2x
TL Smart Missiles
1x Broadside Shas'vre
1x Advanced Targeting System
1x
TL High-Yield Missiles
1x
TL Smart Missiles
6x Missile Drone
All of this for 557 points.
PS. Neuroweb System Jammer is a really good defensive system for only a pair of points!
Wait, changed my mind again

2 Broadsides Shas'ui with Target Lock
1 Broadside Shas'vre with Advanced Targeting System
1 Commander with Early Warning Override
This way you get all the bonuses.