I prefer to keep them split!
I’d rather have higher effort and more recovery with each having their own day, vs maybe sacrificing either effort for one OR recovery within a week just to spread volume over the week.

Just think, if I do 6 sets of hams, 6 sets of quads once per week on their own day, OR 3 sets of hams 3 sets of quads 2x/ week together
Which do you think would produce more output of effort within a given day and recovery within a given week?

And volume just ends up being the same for the total week but maybe I can’t give full effort to a main movement for hams if My body is spent from a full effort set of quads if on the same day
I’d rather go all out on quads, recover, go all out on hams, recover, repeat