Me and the people I play with have long since decided that were just going to play the characters we want, party "balance" be damned, and make it work however we can. One of the longest running campaigns I ever played in was me as a Bladesinger, a Wizard, a Sorcerer, a dwarven Fighter, and a Barbarian. No healing, no Rogues. We did fine with potions and a cohort Cleric someone eventually picked up.
Making a party work despite not having the "necessary" classes makes it even more fun. And forcing someone to play a class just to have certain abilities in the party really sucks.
We play what we want to play. If everyone in the group wants to play a Fighter, well then by god, we all play Fighters an make a campaign around that.
I think the party your group is making sounds really fun, and I really think all the cries of instant death for them are quite exaggerated. Accomodate them if you have to, even. Put in lots of healing potions for them to find. Have a handy local NPC Cleric to heal them when they go back to town.