In my ongoing Rise of the Runelords, I yelled from another room "what do you want to be?" and we ended up with two rogues, one combat one skill, two fighters one finesse one brute a ranger who doesn't like using his bow and a paladin that is better suited to be a wizard. needless to say after a few sessions (two) Mr.NPC Cleric joined the party, he's going to be a key feature and story character, but for now hes the party heal bot cause if they didn't have one (the paladin won't heal on principle, he sees others that need healing weak)
Now this is for the group I DM for, the group I play in we have no cleric and seem to do fine with a (Rogue, Ranger, Rogue/Wizard, Fighter/Ranger and a Wizard/Fighter) So it might be my DMing but my group usually NEEDS a cleric and only one person doesn't mind being a cleric. I was thinking of making it a round robin character XD just so they get a glimpse of being a cleric.