Additions of generic followers to give variety to the matter, there is also an Administrator for Golden Hills and a sacrifice for Boethia.
 
I was inspired by the work of (Convenient Vanilla Followers - Hold Guards) and made a couple of guards from each region, including Raven Rock, to accompany you on your adventures.
These guards are found in BARRACKS in each region and have customized Classes and combat styles to make them skilled in physical combat (melee and ranged).

I've added an administrator to Rorik's Village Inn so you don't have to leave a follower in charge at Golden Hills Plantation.

I have added a sacrifice for Boethia to the Hall of the Dead in Whiterun.

Added followers to obtain their blood for the Daedric quest Discern the Transmundane.
They are in the prisons of Whiterun, Riften, Solitude, Windhelm.

And finally I have added a few followers to give more variety to Skyrim's followers. I have tried to mix the races and classes because in Skyrim, being a land of Nordics, the other races are few.
This will require RDO-Relation Dialogue Overhaul because the voices of these new followers do not have the necessary lines in vanilla and either cannot be recruited or never speak.
These are in:
RiverwoodTrader - Support Mage - High Elf F
The Frozen Hearth - Support Mage - High Elf M
Ivarstead Inn - Barbarian Light - Argonian F
Nightgate Inn - Warrior Bow Light - Khajit F
The Mortal and Pestle - Warrior Dual Light - Khajit F
Falion House - Warrior Magic Attack Light - High Elf M

Credits
The faces used for the guards are from:
Shiva's Beautiful Presets at Skyrim Special Edition Nexus - Mods and Community (nexusmods.com)