How is it debatable?
Releford was First Team All-SEC last season and averaged 14.9 points very efficiently (47.6 FG%, 40.7 3%). He was also on the All-Defensive team.
Lacey averaged 11.3 points (39.2 FG%, 37.3 3%). He did average slightly more assists than Releford (3.2 to 2.5), but Releford didn't turn the ball over as much (2.3 to 1.8). Lacey isn't much of a defender.
I'd honestly rather have Levi Randolph than Trevor Lacey. Lacey isn't too dissimilar from Golden. Lacey is more of a shooter while Golden does most of his damage inside the lane, but still... They're both strongly-built combo-guards who can score and play PG if needed, but also struggle defensively.
But you're right that it's never a good thing to have key players transfer out. I do think Alabama will be fine, though (just as Tennessee will be fine without Golden).