Masking upperbody for melee swings, dealing with hip movement in anims

I want melee to be able to move and swing at the same time, so I mask the upper body (and aim it with FinalIK), and swing. This works fine. But all of my melee anims I have bought almost all have some sort of twist (or turn into the swing) of the hips and to some small part the legs. This makes sense, as you wouldn't swing with just your arms, you would have a follow through. But the upper body mask won't use the hips so the upper body doesn't reflect that hip movement, and his swing looks a bit wonky (and typically on a right hand swing, goes too far right as he lost the hip movement and the follow through).

Is the only way to solve this to have swing animations constructed specifically with no hip movement? I.e. is this something that requires custom animations for?

Note: I cannot use root motion, as I am working in a server auth environment, nor do I want to use the full body animation as your feet will slide during the animation.