No expert but..........As a general rule (not model specific): will a good stock improve it? Yes.
It does ok now should I mess with it? Depends on you, if it already exceeds your hopes: count your blessing and be happy.
If you want to make it as accurate as it can be: continue with your plan to upgrade.
If you do your upgrades correctly I would expect the end result to cut your groups in half but there is only one way to find out for sure. I can not (and no one can) guarantee anything more specific except it will not make it worse if it's done right..
You'll never get "all she's got" in mass assembly, It's not even theoretically possible so can it be improved? YES.
Does it need it??????? You tell us.