Interesting post and question. I have only shot a few animals with bows in the 40's, so I don't have the direct experience that some others do. Just some things to consider:
I have always been of the belief that you increase your odds of finding an animal with better blood on the ground, and with increased cutting area based on the blades. Even at that poundage on soft animals like a deer, it will be very unlikely that you will get substantial penetration gains using a 2 blade over a woodsman of normal diameter VPA 3 blade.
If you encounter hard bone, which is almost an oxymoron regarding deer, that would be an example of where a 2 blade would be a better choice. Consider if this is likely to be of more benefit than a larger head in most situations before deciding. I would argue that if you encounter hard bone, the trajectory/angle of your arrow is in a place unlikely to hit the vitals, and you will likely have problems irrespective of any possible penetration gains.
If you decide to hunt turkey with their tough feathers, you certainly may benefit from a 2 blade on certain angles. The downside is the vitals are small, and the smaller the head, the tougher it is to hit the vitals. That being said, A small 3 blade doesn't improve that dramatically.
If you choose to hunt hogs, I would probably choose a 2 blade because every bit of penetration may help on a tough hog. I shoot more energetic setups, and definitely prefer 3 blades for hogs.
The bottom line for me is, vpa and woodsman heads don't penetrate all that much less than a 2 blade on soft tissues, and generally speaking give a better blood trail, all things being equal, so even with a light weight bow, they would be my choice. Pro's and Con's to everything. Good luck with your choice.