Comparison not 20 points unit versus 30++ points unit who wins but overall deck infantry composition price/performance, veterancy and availability. Also utility of cheaper more available infantry with still decent performance like 15-20 rifles or 25 vetted machineguns and such.
Well, I dunno. Speaking of fair comparison, we could take beta's 12 SS vs 3rd AD, both armored divisions, both limited to a small number of infantry, but I would pick grenadiers over rifles any day. Overall I would rather pay 35 pts for a grenadiers in Opels than 20 pts over rifles in Bedfords because of the sheer power they provide. They're no quite good in CQC, of course, but x2 MG are such a powerful tool.
The only downside is that the grenadiers are considerably less available, that's true. But Axis infantry deck from Beta, Luftlande that is, relied on even cheaper and even more numerous weak infantry. And at least my own experience tells me that bunch of reservist + couple of good squads with powerful MGs are much better than an equivalent amount of mediocre troops. That could be just my playstyle, of course.