I'd look to prune out some of those excess branches. It looks like you more or less have the trunk already established with some taper - too many branches growing too much will only hurt you by reducing taper or even introducing inverse taper. Looking at the bare naked picture, which branches do you want to keep, and which ones do you want to get rid of? It strikes me that you'd want to, at the very least, remove branches sprouting from the same point so that there's only one branch coming out of a given point and at a given level. The overall look is bushy, untamed, and wild - it lacks the clean lines, fractal structure, and taper to present as a big old tree.
So pruning - yes. I wouldn't defoliate until I had my main branch structure built. Defoliation is for reducing vigor and/or increasing ramification - neither of which you really need to do right now. As to which branches to prune... that's something you'd need to do after some careful consideration and thought as to the final image you're wanting. Just keep in mind that once you cut it off, it's gone, and that letting the branches grow too long will have detrimental effects on the tree's form. I'd try playing around with it in GIMP to help find an image you like, and then use the snips to realize it in reality. Maples tend to have a smoother bark - you'll probably want to pay particular attention to how you treat the wounds after pruning so that you can minimize scarring.
since ive gotten my trident maple this spring {April} ive pruned and defoliated, maybe 60%, it grew back, got black water spots on 100% of the foliage from over watering, recovered from that been defoliated 95% and since has grown back 100 % ive had it since april, thats only short of 2 months ive had time with mine and when it got here it was fully leafed out. Im in GA.
If you defoliated today, in 2 weeks it would be fully leafed out already I would say.
maybe wait for some one elses answer tho, considering my little knowledge so far!
There is a world of difference between Georgia's climate and Wisconsin's. My horticultural practices are very different here in Michigan than they were in Texas, and things I could get away with there I could not do so cavalierly here! Real winter doesn't go south of the Mason-Dixon Line.