Still doesn't really make much sense to me.The actual functional difference between the two stats is a lot smaller than the effect that your level bonus should have, because it depends on the difference between the skill level of the stat you're emphasizing and the ones you're not.
For example, let's say you have a level 50 Kaguya that you were doing your "hybrid with MND slant". You might have 50 SKP in MND at that point, and only 30 SKP in MAG, but you spent all your level ups in MAG. However, a difference of 20 SKP levels in MND only means an additional 60% more MND compared to MAG, but a full 50 levels in MAG means you got 100% more MAG than MND from levels. So your "hybrid with MND slant" is still technically emphasizing MAG in the long run.
To put it another way, whenever you're considering focusing on different stats for SKP and level ups, if the SKP cost of raising the stat your focusing ever surpasses 150% of the cost to raise the stat you're spending level ups on, then you're no longer spending your resources efficiently. That 150% threshold is fairly low as far as SKP levels are concerned, as it will pretty much ALWAYS result in a much lower impact on your stats compared to how you've been distributing your level ups.
You can also look at it as meaning that the opportunity cost and gain from your level up bonus is equal to 2/3 of the SKP cost needed to get another skill level into that stat. Because of this, it's actually most cost-effective to be spending your level up bonuses on whichever stat you've emphasized the most in terms of SKP. If you're spending, say, 3 level up bonuses on MAG and 2 SKP on MND, but MND costs you a lot more than MAG to skill up because you emphasized it for SKP, then you probably could have spent those 3 level up bonuses on MND and gotten maybe 3+ levels of MAG out of that SKP, for a net gain in your total stats.
As the game goes on, it only gets more and more impractical for the difference in skill levels to grow greater than your overall level. The mechanics of the game encourage you to keep your SKP distributions even, thus minimizing differences in skill levels, but your level will keep growing linearly. In the long run the opportunity costs from level ups are actually far greater than what you buy with SKP. Thus, I'd define focusing on a particular stat as spending comparatively limited and precious resources (i.e. level ups) rather than something relatively plentiful (i.e. SKP).
Does this make sense, or should I give some specific examples (with numbers) to illustrate what I mean?