If you want to replace a 3 kg motor (Bosch 750) with a 600 gram motor (propdrive 5060) you'll need more of'm.
Also, smaller motors run faster (the slowest propdrive is 270 KV, 2 times faster than the Bosch 750)

In short, if you want to have the equivalent of a "bosch 750" drive in propdrives 5060 you want at least 4 of'm, and be prepared for a higher gearratio.