Personally I only consider energy as far as it takes given amount at the tip of a bullet to get it to open.
For those bullets an impact velocity of 1800 fps seems to be recommended for the lower threshold for them to reliably open. That would translate to around 1050 ft/lbs.
I have not proved that to be true or false as that would be about an 1100yd shot from my rifle, and I'm not there yet.
I'm with Cliff on this one. The design of a .357 hollow point allows it to open and mushroom effectively at those low velocities. The VLD's design is way different. 1800 ft/s is the published minimum velocity for them. I'm looking at the same things to find the maximum effective range for my 7mm RM.
I'm sure it will kill a deer at the lower velocity, but a marginal shot may mean a wounded deer getting away.