fvtt-dndbeyond-character-sheet VS MonsterBlocks

There's also the full DNDBeyond character sheet module as well as the compact one if you want that style.

If they're used to DnD Beyond, then you might be able to kill two birds (character sheet and rolling) with one stone by using the Beyond20 browser add-on (though it might need some tech savvy to install). I don't use it (nor DND Beyond) personally, but it should let them make rolls right from their DnD Beyond character sheets. Or if you'd prefer to keep things contained within Foundry, there's also a DND Beyond Character Sheet for 5E which should look a lot closer to what they already use.

If accessing the monster actions is the problem you might try the Argon HUD or change the default sheet layout to something like the dndbeyond character sheet module or monster blocks so it's more familiar

I did find this module, which attempts to recreate the look of the dndbeyond sheet but has some clear differences, so there's a bit of precedent for it, but I just want to make sure I handle this properly.

If accessing the monster actions is the problem you might try the Argon HUD or change the default sheet layout to something like the dndbeyond character sheet module or monster blocks so it's more familiar

Monster Blocks: Alternative NPC sheet to display things similar to the Monster Manual

Monster Blocks