You guys wanting 6 chars are looking at this all wrong. You seem to be basing the need for a 6 char balanced party on older games based on older versions of DnD where a tank and healer were crucial to party survival. 5e classes are more customizable and more self sufficient. You can easily run a group of 4 with no dedicated healer. Self heal options, potions, food heals, etc. are easy to come by. Anyone can attempt any skills, and can be proficient in them depending on background including lockpicking. Even without proficiency you only lose like +2 in the early levels, not a big loss.
I have no tank, just dps fighters (GWF EK and BM Dual Wielder), and the cleric has only used her heal spell like twice when i was level 1. I used the rogue primarily for sneak attack as it seems all of my characters dont really have much trouble picking locks, then swapped him for dual wielding battle master who just provides more toughness and dps overall. I have not had any issues swapping out specific role members just trying a different party makeup as i still dominate pretty well in battle and handle anything else outside of combat just fine.
Pretty much any combination of 4 is totally doable guys even if you need to be a little tactical about it