I noticed from your profile that you're at an MMA gym now. Have you found the attributes and movement patterns you've gained from spear shaking to have noticeably altered your striking game?
Any time. From your questions, I gathered that you might have concerns over the fact that the pelvis rotates so that it's no long fully facing the front. Is that the case?
For grappling, yeah, I'd rather keep my hips square as much as possible because turning sideways opens me up to counters, aka all the big pickup counters to forward throws that the Soviets introduced to judo competition. But in a game where striking is involved, I find (for me) that it's advantageous to be able to sometimes use the shoulder roll/philly shell type defense. I know that some people think that can't be used in an MMA or kickboxing environment, and that in that environment one has to square up and stand tall. However, if you take a look at Josh Barnett, for example, he does use the shell/shoulder roll in MMA:
When you say hips, could you specify which muscles you find overly tight when the back leg locks out? I ask ,because its difficult to communicate these things in the written word, and I find it's an easier basis for discussion when we can use anatomical terms. That way, we all can agree what we mean by things like "hips," "back" etc.