He's definitely a 4 but I do think he CAN play the 3 sufficiently in certain match ups.Putting Lyles at the 3 feels like that diminishes his value. His value is stretching out bigs. His value is being able to take bigs to the rim. It's like when some writer suggested Porzingis play the 3 last year, it just doesn't make sense.
Lyles can create efficient opportunities on offense that Kanter could not. The ability to be a threat from deep and also create from deep with his drive and kicks, hitting cutters, etc are a lot more valuable than Kanter being able to bully into a post score and grab a few offensive rebounds. This is if you consider them equally bad defensively (which I actually do not)
If I'm not mistaken I think LaMar Odom started out as a 4 or a 5 for the Heat too, then eventually settling as a 3 for the Lakers ?