How have your games gone with no dedicated healer?

This has probably been asked many times before so please forgive me. My understanding is that PF2E is balanced around being full health between encounters but not necessarily having a dedicated healer during combat. We are playing the the Free Archetype Alternate Rule. The campaign is from levels 11-20. With that understanding my party has chosen not to have a more dedicated healing role and decided to have our gunslinger pick up the medic archetype. Do you think this will be enough, or should I encourage them to invest more? How has your games gone with similar investment into healing?