I took the spectra from the online data published by Schiavon, not from the website.

Name
Age (Myr)
[Z/H] (Z_solar=0.02)
residuals
Model: Pegase.HR
NGC104 (47 Tuc)
10758.2 -0.623
1.02468
NGC6258
9293.73 -0.112
1.75712
Model: BC03
NGC104 (47 Tuc)
7784.75 -0.461
0.990405
NGC6528
6031.33 0.125
0.987978
Model: MILES
NGC104 (47 Tuc)
11782.4 -0.609
0.584721
NGC6528
9711.22 -0.135
0.695565

In the above results I have a preferences for the results found with MILES, since the residuals are smaller. Its the only objective thing I could figure out.

Note that the pops in MILES are solar-scaled pops, so I have no constraint on the abundance ratios.