Assuming the causes of the crashes are not caused by faulty hardware, but by bugs in software, a faster CPU at best means it can crash faster, but doesn't really do anything for avoiding crashes.
Or are there some HW restrictions in tablets that make the SW more difficult to be made stable?
I have no experience with or knowledge about iOS, so my guess is as good as yours, sorry.. but my guess is yes, either that or maybe the browsers for it do things slightly differently. At any rate, I think unless software makes assumptions about hardware/memory instead of checking first, "weak" (but otherwise not faulty) hardware should not lead to a crash.