As the Krana is the one using the Bohrok and not the other way around, an ordinary Krana probably couldn't pilot a Kal body, much in the same way that a Matoran cannot wear a Great Kanohi without hurting themselves. However, by the same analogy, I'm sure a Krana-Kal could pilot a regular Bohrok, in the same way that a Toa can use a Noble Kanohi.