In my crankbait building, I've found it helpful to think of a crankbait's actions as wiggle, the X shaped movement of the lure's nose and tail as viewed from above, and wobble, the amount the bait moves/rolls from side to side as viewed from the front.
The bigger the X, the wilder the bait's side to side action, and the bigger the wobble, the more water it displaces on the retrieve.
I need to add ballast to all of my PVC trimboard lures to get them to swim right.
I typically use a successful commercial crankbait as a model, floating it in my 5 gallon water bucket to see how it sits at rest. I add ballast to my lures to achieve that same "angle of attack", and then , once I've gotten a lure to duplicate the commercial lure's performance, experiment from there.
I've found that adding my ballast at the belly hook hanger's location, and as low as possible, give my the widest wiggle (X ing) because both the nose and the tail are the lightest and easiest to move when they have no additional weight, other than the line tie/lip, and tail hook and hanger. It also produces the most stable lure, one that won't roll over no matter how fast I retrieve it.
Splitting the ballast, and installing it in front of and behind the belly hanger, dampens the wiggle. The farther apart the weights are, the more they act to deaden the wiggle, because they become counterweights.
I've found that the higher the ballast is in relation to a line from the line tie to the rear hook hanger, the more the lure wobbles. In my crankbaits, I still put the majority of my ballast weight at the belly hook hanger, but I've found that by moving up to a third of the ballast weight about that line tie/rear hanger line, I can get more wobble in an otherwise stable lure.
I'm afraid you'll have to just try stuff to really learn how to ballast whatever lure you're making. Of course, if you're smart like Dave, you can figure it out as you design your lure on the computer. I've never been able to do that, so trial and error has been my method.
Everything I know about lure building I've learned here on TU, from people like Bob P and Dave, who have shared with me, and from just trying stuff to see how it works.
Good luck, and let us know how you progress.