Other Flash Units with A6000

[pictureman]

New to this forum and I don't own an A6000 but if I could ever get a Metz 54MZ3 to work with one, it would be mine.  I own 3 Metz units that were used in my old but retired Wedding Photography days and I have slave units to drive two of them. I love them and I use a lot of flash. Problem is Sony offers no ability that I can find to adapt these strobes for their cameras. I understand the A6000 will fire a maverick flash unit even though you can't use TTL or Auto. Here's what I don't understand. If I set my Metz on Auto, set the F stop to say f8, ISO to 800 and the camera on M, f8, 1/60, why would I not get a correct flash exposure as seen by the Metz? Hoping you have an answer so I can order an A6000 or A6500 soon.  Thanks in advance.