For an anatomical artistic study yes, use all the polys you can, where you just want to sculpt a form (I would have just used Zspheres and then gone from there in that case).
For a topology study (which the title suggests) then no, build up from the base, if you get the base correct before going into zbrush then you dont need to fight the topology, it will work with you, if your just looking at topology then why use Zbrush at all?
In all honesly the I feel the most artistic stuff in 3d is where the lower sub division levels describe most of the form and look correct, Z's pass is the icing on the cake to "ping out" the detials, not to make the base, have a look at some of Steven Stahlberg's works Antropus Costa's too, they get superb anatomy from the base mesh.
Anyway its your model and your study
Gect, yeah haha.
"No pressure, no diamonds" Thomas Carlyle