What do you mean by "mathematical"? Based on some ideal curve or ideal ratios, and if so where did you get them from?
Nimble Obstructionist seems bad, especially as a 4-of. If you want a 3-drop that can carry equipment to victory and you don't want too many Cliques, what about
True-Name Nemesis? Or maybe 2 Clique + 2 TNN?
Flickerwisp is another option that has a lot of utility.
Supreme Will seems weak.
Spell Pierce seems better, since you have no non-FOW counters under 3 mana which is awkward (even your Stifle effect is 3 mana) and that limits your ability to interact or protect your pieces. You could also consider a mix of
Snapcaster Mage and Spell Pierce. Snapcaster gives you those extra modes of Supreme Will: you can have more counters, or more cantrips, or even more spot removal.