Everyone has their own ideas and preferences when it comes to modding and I'd really encourage as many people as possible to pick up the tools and give it a go - I recently uploaded a 'mod resource' in the form of some basic mercenaries along with instructions on how to add them to the game so check it out if that sounds like something you'd like to play around with.

If you'd like to customise this mod according to your own tastes then here's where I'll try and offer help and advice on how to do that.

First you will need to download and install 'pack file manager' (PFM), it's really quite straight forward but if you are having issues then you can always visit the support thread on TWC.

https://sourceforge.net/projects/packfilemanager/
http://www.twcenter.net/forums/showthread.php?759230-PFM-5-0-Warhammer-2-support

Once PFM is installed and setup - find where you installed total warhammer 2 and find the data.pack file. This is the main data file where most of the information you need can be found - don't make changes to the data.pack file, just keep it open in a second window and use it as a reference point.

Next find where this mod is saved and open it with PFM, it's called 'c2_sartosa_public' and mine is in SteamLibrary\steamapps\workshop\content\594570.

To begin with we'll change which VC faction can use the new Sartosa units.

Open the 'building_units_allowed_tables'.

Here you can see that the table has entries that look like this:

wh2_dlc11_vampirecoast_port_1 / sartosa_gunners
wh2_dlc11_vampirecoast_port_2 / sartosa_gunners
wh2_dlc11_vampirecoast_port_3 / sartosa_gunners

This means that the sartosa gunners unit has been assigned to be recuited at the lvl 1, 2 and 3 port building. We can leave this as it is, or if you want to move them to another building look at the data.pack file and find the same building_units_allowed_tables there. Then pick a building you want to use

e.g. 'wh2_dlc11_vampirecoast_military_ranged_1' to give them to the lvl 1 vampire coast ranged barracks or 'wh2_dlc11_vampirecoast_ship_gunports_1' to give them to the equivalent building in the legendary lord ship chain.

If you want them to be recuited as well as, rather than instead of, another building then just add a new row and copy the required information across including a unique 'key' number where necessary.

This is how the bulk of basic modding is done - it's litterally copy & paste.

To change which faction can use the Sartosa units open the following tables:
unit_variants_colours_tables
units_custom_battle_permissions_tables
units_to_exclusive_faction_permissions_tables

Replace all the entries of 'wh2_dlc11_cst_pirates_of_sartosa' with your preferred faction:

wh2_dlc11_cst_noctilus
wh2_dlc11_cst_the_drowned
wh2_dlc11_cst_vampire_coast
wh2_dlc11_def_the_blessed_dread

That's it! It's that simple, just a copy and paste job. Save the mod and your done.

Now if you want ALL the VC factions to be able to use these units at the same time then delete the 'units_to_exclusive_faction_permissions_tables' table entirely. Then right-click on the mods main 'db' table. Select 'Add' then 'From Pack' then pick the main data.pack file and add in the 'units_to_groupings_military_permissions_tables'.

Delete all the rows in the table but leave in the two that say:
wh2_dlc11_cst_inf_sartosa_free_company_0 / wh2_dlc11_group_vampire_coast_sartosa
wh2_dlc11_cst_inf_sartosa_militia_0 / wh2_dlc11_group_vampire_coast_sartosa

Then add in 8 new rows and copy & paste the names of the new units added in the mod:

sartosa_swash
sartosa_gunners
sartosa_hal
sartosa_cannon
sartosa_mortar
sartosa_knights
sartosa_marauders
sartosa_exiles

Then change the 'wh2_dlc11_group_vampire_coast_sartosa' to 'wh2_dlc11_group_vampire_coast' and add that next to all the new units to allow them to be recruited by the main VC factions. Since we deleted the previous table that added the units to sartosa exclusively you will need to add in 8 more rows and copy the new units in again, then add 'wh2_dlc11_group_vampire_coast_sartosa' to allow sartosa to recruit them again.

That's pretty much it I think. You may have some trouble with the TW2 launcher re-downloading my mod when it notices you have changed it so my suggestion would be to save your changes as a new mod next to your data.pack file in the main TW2 folder - disable my sartosa mod in the launchers mod manager and activate your custom version.

Let me know if it works!