Well, yes. I would have Spinel there from the start of the series. I would have her as a constant source of support for Steven and have him open up to her.
The way they went about it was just Fanservice. Connie should NOT have been made to be the one who helped Steven and her stupid and hypocritical speech in "I Am My Monster" just made it even worse.
Instead of having someone who, I dunno, CAN ACTUALLY RELATE TO STEVEN AND WHAT HE WAS GOING THROUGH, they had Connie who doesn't know shit and honestly made things worse in many cases.
*sarcasm* The brilliant mind of Becky Sucrose, everyone!