Programs, Gear are just tools to be used towards the same goal Strength. The key is determining how best to set it up per the individual.
Can a Raw lifter get stronger in his lifts using gear? I offer why are there Partial movements like Rack pulls or walkouts, Rev Bands, chains ect.
Go back to how Paul Anderson use to lift, lots of partial movements.
There are many benefits gear can offer, one being the mind gets use to handling heavier loads as does the your CNS. The answer to what works is what you can recover from. When your talking about 900lb raw squats your time frame for getting gear work in addition to your raw work I think is just something most elite's have had a hard time finding the proper balance. Plus its simpler to just train raw.
Gear you have to keep sized correctly pia but if you don't your numbers will vary considerably or just not fit entirely.