The thing to remember is that the players who have made a genuine mark at A-League level (Riera, Siggy, Krishna) were head and shoulders the best players in the Handy prem when they signed for the Phoenix. I'm not sure there is anyone currently that step ahead of the other players in the competition.Now that could be because the Handy Prem is stronger now but we'll assume not.
Any Handy Prem player would be a gamble and a back-up to start with.
Most of the best youngsters are with the Phoenix or have gone overseas, Payne and TAHW are already trialing and if they come through it (particularly TAHW with injury concerns) then they probably need a season to get up to speed - based on Siggy and Krishna's experience. There are a couple at Team Wellington you would think are a chance (first thoughts Shrijvers and J-H S) for some time at the Phoenix but it's not like J-H S is unknown to the organisation already.
Gulley two seasons ago was definitely at the very top of the players in the Handy Prem and while his form wasn't as good for Team Wellington last season I don't think you would claim he made the step-up albeit he ended up chucked in the deep end when Louis went down.
There are quite a number who have been with the Phoenix either trialing or just in the organisation that will still be on the radar but like I said none of them turn up week in and week out and dominate every Handy Prem game which makes it a big call to sign them to a first team deal at A-League level.