so aps is the same as ZF and they own thb?
APSF and ZF are close but I don't think they're exactly the same, or at least their suppliers are extremely similar. THB is owned by APSF or at least tangentially related somewhat.
The key difference IMO from what I've observed is that APSF can do clone movements, ZF doesn't do shit.
Notice this :
APSF were the bad boys to release clone movements. They did the clone A4302, the Portugesier/Big Pilot movement, now they also did the 15407 semi clone and now this 4401.
ZF rarely or basically never makes any high end clone movements. They stick to well known movements or modify them (i.e 15202 > modified 9015, etc). The closest they did was their Breugrt 7097 which is still a modified movement.
And somehow they always manage to obtain APS movement. ZF 15500 has the 4302.
This is just speculation of course I'm not on the ground or related to any factories, it's just what I've seen.