Coming back to this. I think maybe this is really the way to go with the set.
I tried to think of an interesting thing to maybe add to the set, but really, it just needs a few tweaks.
Focused Burst...Total Focus Level Damage. Simple. The fact that this attack has any range really means very little. You're a melee AT, it's going to be used in melee more than range and it's use as a runner pick off isn't that big of a deal. I'd add a hold effect to the attack as well, but I like having a Hold in a set, so admittedly could be biased there. For sure Total Focus level damage on this.
Concentrated Strike...Give it crit damage! Preferably FULL crit damage! That's all it needs. I'm not sure it really needs more than that. Doesn't help Tankers/Brutes as much as it will on Stalkers/Scrappers, but I don't think the animation needs tweaked. The first three attacks are good enough for regular mission clearing. Give Focused Burst the above mentioned tweak and you have another solid for that aspect.
After that, one can either skip CS...take it for those ST DPS moments (AVs/GMs/EBs)...or just use it for regular missions and accept it's longer animation.
Those two tweaks and it improves the sets DPS without making it the new top tier, just improved.