Any individual in my party initiates whatever. They all have roles and generally can choose, well, who you want initiating things in different areas and situations. Exactly as what naturally happens in MP but with less...chaos.

I'm also swapping around party members all the time at camp because that's kind of why they're there. Whoever's got the most roll advantages for the situation, dialogue in town, imitating combat, doing puzzles, etc. they're on point. Since my custom is a bard, unless in town talking, someone else is always up front.

A protagonist isn't synonymous with "a leader" in D&D unless someone's choosing to roleplay one of the characters like that. I guess a Paladin or something might make sense to, especially roleplaying oathes...