The speed should not be increased, that is how fast it goes;
Speed 59 mph (95 km/h)
basic 373 mi (600 km)
max fuel 497 mi (800 km)
fording 2 ft 11 in (0.90 m)
side slope 30%
The soft attack of all Anti Tank units is lower, A TOW is not a weapon to use against soft targets. It's only other weapon on the VBL-AT version is a coaxial 7.62mm MG. You also have less crew than on an VBL-RC unit, where the crew could get out and support soft target attacks with their own weapons.
ATGM 1 x MILAN ATGM launcher
Ammo load 6 rounds
Coaxial 1 x 7.62-mm MG on ring mount
Ammo load 3,000 rounds
Elevation -10/+50 deg
As for the buld time, as a hard target it is one of the faster building units. Anything with that level of armor is going to take a while to build.
The VBL is an armored light truck with a sloped glacis and a boxy crew compartment. The front-mounted Peugeot XD 3T diesel engine is identical to a common commercially available powerplant. All glazing is bulletproof, the tires are run-flat type and the welded-steel body tapers in toward the center above the wheel line.
Based on that description I also don't see a need to increase its defence values.
Don't mean to jump all over you, just wanted to share how I came up with the values that are there. Please feel free to add more details if you still feel that the values should be changed.