It's basically impossible to run grain parallel to 3 different lines. So I assume you're thinking to sheet from the LE back with some, from the TE forward with some and possibly some down the middle. Trust me, it's been done.

That extra work might be worthwhile to some, but in fact balsa differs enough that it's really not worth the effort. What is worth the effort is to sort all the sheets by weight and strength. Use the strongest where it'll be down the spar and forward to the LE. Throw out the weakest and find better.

If you're sheeting foam, it's not so important. The foam provides the same support that webbing provides spars, only it does the support everywhere.