Not for okw and especially against Comet/Churchill/T34-85/Dozer M4/Ez8/KV1/KV8. I put the KV1 and Churchill here due to cost very near medium tank cost.
I was referring to stock mediums exclusively. All of the ones you just listed would give the Hetzer an even larger time window to operate without challenge in due to higher cost. 2x Rak will do just fine against any of the 3 stock allied mediums, and will still do pretty well against most of those except maybe churchill and Kv1
Kv1 and Churchill would be awful at fighting the hetzer, and most certainly do not count as medium tanks. Choosing one of those for your first tank while there's a hetzer on the field already makes no sense at all. You'd be waiting longer for a tank that has no chance of chasing it down...