HST exercise alternation...

Doing two sets of the same excersise will perhapse improve your work capacity for that excersise, maybe sacrificing the frequency benefit if you do it every other workout.

Doing two different excersises may give you the frequency benefits for both excersises, but not so much work capacity for each.

In the grand scheme of things this is a pretty minor detail to be concerned about. Just do whatever is more convenient.

In regards to calves, I just don't see an athletic situation where I'll need my soleus more than my gastroc. So I don't even bother with hitting it directly. It gets worked when I hit my gastrocs. Can anybody refute this?

I don't do any tibialis anterior work either.

DARD

Relatively speaking, gastrocs are hit more in standing, and soleus more in seated exercises.