Forgive me but I thought that the OP was just wondering why his turbine FW experience didn't count at all towards RW turbine requirements and therefore nothing to do with how qualified he may, or may not, be to fly a helicopter as opposed to an aeroplane.
I got that from:
"Well I have over 600 hr turbine time BUT most in fixt wing"
Note: he didn't say "all."
In case you are wondering, I have 40yrs in the game so I'm not another frustrated beginner needing a break to get into a turbine. In fact for me it's good to have the ever increasing demands for experience these days. I fit most of them and can demand more money because I'm getting increasingly hard to replace
.
I've been lucky to have flown both FW & RW. If the choice came down to two pilots to fly my turbine helicopter, and one had flown turbine FW, I'd look still look closely at that individual - all other things being equal.
I just don't see the "magic" required to be able to fly a turbine anything. They are just expensive to stuff up. Preventing that comes down to an individual and their training as much as magical hours in a turbine helicopter only. The OP already has shown he is capable of doing the tricky bit, such as starting a turbine, to the tune of 600hrs. What does the airframe it is in really have to do with that?
I didn't see this as a FW versus RW flying capability argument. Just the powerplant differences.
Perhaps the OP can clarify what he meant if I have got it wrong.