I think free agency plans were always dependent on who was selected.
If it was Doncic, then you have filled the starting SF role, you want a stretch 4 and you need a big who sets good screens and rolls hard to the basket. And ideally one who can be the lone big on defense, protect the rim and rebound aggressively.
That last role is exactly why you'd want Capela. Willie isn't a great screener and isn't the defender/rebounder we hoped he would be though he can switch onto quicker players on defense. Koufos is a great interior defender and good rebounder, but he's not a rim protector or a guy who can switch on to quicker players at all. Capela is a better fit than both and until the team knows that Giles can stay healthy and sees what they've got with him, Capela would make a ton of sense.
Now that Bagley is the pick, starting small forward is actually the biggest need, stretch four is a bit less of a need (partly because the hope is that Bagley can develop his outside shot further but mostly because there won't be as many minutes to go around) and a big like Capela makes less sense. To help Bagley develop you don't really want a center who can only operate close to the basket as it just crowds the lane.
So while I love what Capela has done with the role he was given in Houston (surrounded by wing shooters and two shooter/creators in Harden and CP3) he isn't a good fit for the Kings IMO. Especially with the money he'll command.
So it isn't that Hezonja is a better player than Capela. He isn't. But he's a better fit and provides more value relative to what he's likely to sign for.