Are they US citizens and/or can they easily get long term US Visas?
What is their income level? If you are using it a lot, an RV can be an inexpensive way to live but if we are talking some of the staff from poor countries, it may be more than they can manage.
A Class C with Toad would be a reasonable option. An electric bike might be a nice addition but not a replacement for a Toad. Unless you go very small, it's a pain to pack up the MH every time you want to get groceries or do a driving loop at a national park...heck many of the great national park drives are limited to vehicles under 20ft.
If they are minimalist, a pickup camper or camper van would be a viable option. The come with their own set of trade offs (both good and bad).
I pickup with a travel trailer offers probably the best cost to space alternative. Both pickups and trailers are widely available. Keeps registration, maintenance and insurance costs down compared to two separate vehicles and even a small 20ft trailer is much more spacious than a truck camper/camper van.
A lot depends on what type of travel they wish to do.
Yes, you have to factor storage in but if you do a little research, you can usually find it for under $100/month (no you won't get that next to the airport in NYC).
Tammy & Mike
Ford F250 V10
2021 Gray Wolf
Gemini Catamaran 34'
Full Time spliting time between boat and RV