As much as its derided as the bane of all RPG existence online, among players its not uncommon.
They want advanced Heroquest or something between board game and RPG which is also pretty common.
Warhammer is pretty intimidating, but would be a good fit.
Warhammer's rules are dead simple for wargames. It's the Entry Level with loads of lore.
And several OOP titles that are perfectly suited for small group play...
Necromunda - gangs in a hive on a hive world. Doing it as one gang for players vs GM gang...
Mordheim - set in the WFRP world. Otherwise, it's low tech necromunda
Gorka Morka - Goblins. Mostly compatible mechanically with Necromunda.
Inquisitor - generic 40k, but detailed character damage mechanics. Uses D100 instead of d6... Almost, but not quite, to being a proper RPG.
All are intended for "Narrative Campaigns"... with tactical battles as minis wargames. Adapting them to gridded play is simple.
If you don't want to print pirate versions of the Inquisitor 52mm figs, use 28's and cut ranges in half.
Also, further back... Space Hulk, Space Crusade, HeroQuest, Advanced HeroQuest.
I have a weird suggestion: try finding a copy of Tunnels & Trolls and see if they can grokk it. T&T is not mechanically rigorous, but you can go from zero to hero with some luck easily. As GM its super easy to run, and you can control the power flow pretty easily. Combats are big dice pool rolls and you can throw low MR (monster rating) monsters at them to make them feel stupid powerful....if they have good math skills they will see through the veil and realize the odds are stacked in their favor (or against it if you feel mean) but if their maths are bad then they will never notice. T&T is all about action and dungeon crawling, and while you can inject roleplay into it all you want it is not in the least bit necessary. Like with D&D 5E, your level of inventory management is "set to taste" and you can easily ignore that component if you want....or let players decided.
If you try this idea, look for a copy of 5th edition T&T or later.
There's much derision of Deluxe by the OSR crowd, but Deluxe is a smoother experience.
That said, 5th is available on Drive Thru (as are 1st, 4th, and Deluxe)...
But I'd honestly recommend Monsters! Monsters! deluxe ed — 2.7 is the numbering — as the huge array of kindreds to pick from, each with a special ability, makes each cahracter unique. Its still T&T mechanics, for good and bad...
The problem with T&T — and M!M! — is the extreme blandness of combat if they don't use "stunts" (aka Stupid PC Tricks), and if the GM doesn't allow breaking a combat scene into multiple separate fights based upon who is where in relation to others.
Further, there is no balancing fights in T&T/M!M!... due to the expectations of stunting, your best bet is average combat total... Without stunting, anything less than 80% of the PCs is a speedbump; anything more than about 125% makes the PCs the monsters' speedbump. Stunting can swng that a lot. There's a lot unsaid in all editions of T&T... such as balancing encounters, how to adjudicate effects of failed saves (There's a rule in one adventure that each two points of stunt fail is 1 point of past-the-armor damage, for example. I've oft used that in play.)
Once one gets players using stunts, that balance goes away. But the game also gets more fun.
