Gonna give this some serious thought. I think you have to use as the benchmark how the player was ranked/regarded internationally , and not their performances in the NBL. You could argue that Sengstock had more of in impact in the early years ( his peak) of the NBL than Bradke , but Bradke was clearly the more competitive player internationally in either the 4 or the 5 in his prime than Larry was.
There is the argument that pre Dream team , the international stage was weaker, but if you look at what happened once the OS players , particularly the euros started to arrive in the NBA, the best euro players were starting five in NBA Championship teams. So a player like Smyth, who was ranked as one of the best 3 PGs in the tournament at several world championships and olympics has to be (IMHO) seen to be a better choice than a player who domestically may be argued as been as good or better ( eg a Grace or Lisch if they weren't naturalized ). If Sengstock had been rated as one of the best 5s at a few international tourney then you would have to consider him as at least at the same level as a Longley.
SG has to be between Gaze,Palubinskas, Ian Davies 9 actually player SF) and Mills , Heal's international form ( and euro history) doesn't rate internationally against those 4.
Bogut Longley and Bradke take out the pure big men spots with Ray Borner looking good as well.
Coach - Adrian Hurley
PG P Smyth, Bench Deledova, Mills
SG A Gaze, Bench Palubinskas, (Mills)
SF Ian Davies Bench - any 2 of -(Sam Mackinnon, Tony Ronaldson, Andrew Vlahof)
PF Bradke, Bench, M Nielsen
C Bogut, Bench Luc Longley,
next best Cj Bruton, S Heal, Ray Borner, David Andersen, Joe Ingles, C Anstey
I don't think that Adrian would actually start with that five, but I'm certain he would complain about the team make up, although Anstey and Andersen may have made his first 12.