[asid61]

After actually attempting to create a swerve drive recently:

1. Machinability
2. Weight
3. Easy to assemble
4. Cost

I machine literally all the parts on our team, so I have a bias against hard-to-machine stuff now.
COTS swerve drives are prety much only available from 221, but that's fine. Their Revolution Swerve is very easy to incorporate into a decent swerve design.

To OP: For your 22lb estimate, you forgot to add the weight of the chassis itself. 0.1" thick tubing all around plus bellypan. Many of the recent swerve designs (particularly Aren's basic design) can be implemented without too much extra design work to make a whole chassis with 0.0625" thick tubing weigh around 34-35lbs. A 4-cim WCD might be a few pounds lighter for a very good one.
SWERVE 4 LYFE