This is a list of recommended mods that enhances the factions in OvN Lost Factions in different ways.

https://steamcommunity.com/sharedfiles/filedetails/?id=2548096468
Mod Configuration Tool: Reborn - You can enable and disable the various races in Lost Factions, choosing which ones should remain on the campaign map.

https://steamcommunity.com/workshop/filedetails/?id=1929477606
Expanded Roster Amazons - With this mod enabled the Amazon faction gets completely fleshed out and starts with the custom LL Penthesilea, new agents and all the custom units including RoR from the Expanded Rosters mod. They also have custom buildings, technology tree, missions and rites.

https://steamcommunity.com/sharedfiles/filedetails/?id=2280047630&searchtext=amazon+for+amazons
Amazons for Amazons - Is a submod where if you are using Expanded Roster Amazons and Lost Factions only the Amazon faction will have access to Amazon units and the Amazon units are removed from the Lizardmen.

https://steamcommunity.com/sharedfiles/filedetails/?id=1553259391&searchtext=decos+chaos+dwarfs
Expanded Roster Chaos Dwarfs - Certain events involving the Rotblood Tribe will trigger a Chaos Dwarf Invasion. If you also use the Chaos Dwarf submod along this mod you can play the Chaos Dwarfs on the campaign map with custom LL, Lords, heroes and a full custom roster of units all from the Expanded Rosters mod.

https://steamcommunity.com/sharedfiles/filedetails/?id=1723762666
Tomb Kings Expanded Roster and Campaign Mechanics - Adds a number of improvements to the Dread King Legions similar to what the Followers of Nagash receives in the mod.

https://steamcommunity.com/sharedfiles/filedetails/?id=1158737832
Cataph's Southern Realms - When playing as the Grudgebringers they will have access to some of the RoR from the southern realms mod.

https://steamcommunity.com/sharedfiles/filedetails/?id=1775132577&searchtext=araby
Flamboyant's Araby Invasion - Adds a pirate fleet attack and an Araby invasion of Estalia and Tilea. If you are playing as Ikit, there will be two unique dilemmas for Clan Skyre in which they can choose to deal with the invaders, or attack them.

https://steamcommunity.com/sharedfiles/filedetails/?id=1509595973&searchtext=second+start
OvN Second Start - Gives most playable factions a second starting settlement in exotic locations so you can encounter some of the new Lost Factions and increases the diversity of the mortal empires campaign.

https://steamcommunity.com/sharedfiles/filedetails/?id=2156358839
Changes both the starting names and adds new names which you gain when specific requirements are met to better reflect your ever-growing domain. All set to fit the lore of Warhammer.

https://steamcommunity.com/sharedfiles/filedetails/?id=2156743064
Adds some of the custom units available in OvN Lost Factions to some vanilla factions and races and some other enhancements.

https://steamcommunity.com/sharedfiles/filedetails/?id=2585773129
Turn the Moot into a 8-slot settlement.

https://steamcommunity.com/sharedfiles/filedetails/?id=2391523144
Spanish Translation of the mod.

https://steamcommunity.com/sharedfiles/filedetails/?id=2619086099
Russian translation of the mod.

https://steamcommunity.com/sharedfiles/filedetails/?id=2232546269
Gives some units in the mod custom battle standards.

https://steamcommunity.com/sharedfiles/filedetails/?id=1586646600&searchtext=decline+diplomacy
Anytime the player or an AI faction rejects a diplomatic deal (Player/AI or AI/AI) they will suffer a diplomatic penalty with that factions race but also potentially a diplomatic bonus with a race that dislikes the rejected proposer.