There are a lot of discrepancies between TK and TD armor, but IMHO we all need to look at it like this, if armor is built to Centurion TK level, you're not going to have any issue obtaining basic, PO, and SWAT level from a build perspective. The obvious differences are the knee plate, no shoulder bridges, E-11 holster, etc. We also have our caveats as well such as starting with level 2/Police Officer you have to mimic the original strapping method (it doesn't have to be functional).