Not seeing how either of those are better, either offensively, or defensively, than Turner, Stauskas, Layman, Collins and Leonard. Turner has a career AST% of 19.5 with a career best 30.0 (currently 22.7). He's also 5" taller than Curry. The only thing he does worse that Curry is shoot the 3. Fine, the goal was to surround Turner with shooters. Stauskas, Layman, Collins and Leonard accomplishes that goal.
You seem to hate Turner so much that you are overlooking Curry's deficiencies. Would you feel the same way if Turner was making $2.8 million and Curry was the guy making $17.8 in his 3rd season here? Regardless of what they are being paid, Turner, for all his faults just flat out out produces Curry.
BNM