But I for one, suggest that 'coherence' is an important thing and someone needs to 'lead' that.
Feasibly, it could be an 'architect' or someone in that role, meaning that 'theoretically' you don't need a 'tech lead'.
But I'd suggest in reality, someone should be the 'lead' in one way shape or form.
Maybe they can soften the role and get the devs to understand that it's more of a 'principal' than a 'boss' type thing.