I agree with Sir Humphrey. I wondered why this strata manager wants to make herself busy with this too.
Strata Schemes Management Act 2015 is your friend (again). Refer to “Schedule 1 Meeting procedures of owners corporations”.
You can definitely organise your own meeting amongst yourselves. The procedure is explained in the above legislation.
You could formalise it by passing a resolution at a general meeting. This should not cost a cent if you do it yourself. Once it is recorded in the minutes, you have something to show the strata manager, other owners, NCAT member.
However, the NCAT member would be more impressed by a common property by-law (which costs money).
Whether you have a leg to stand on? My owners corp was taken to NCAT by an owner. She wanted one of her neighbours to remove their dog. The NCAT member asked how long the dog had been living there. Answer: 10 years. NCAT member: “I am not about to remove a dog that has been living there for ten years.”
NCAT members each have their own temperament. Hopefully, if it comes to a tribunal hearing, you get a member who has common sense.