The only necessary change to Dshk is to remove the "sprint" ability.
No, Dshka has a bugged retreat where it's in slow motion for a couple seconds and the crew clumps up, making it super vulnerable to greandes. Sprint is super critical for making retreats when in danger by bypassing the bug.
It's also not as good as you think, it usually doesn't apply the speed boost as much as you think and I play Dshka every game so I know.