Crazyflyingpanda

Hello, I recently decided to try out age of sigmar since I have been playing the Total Warhammer series recently. I bought a couple boxes that a friend wasn't using for cheap on a whim about a year or so ago (Flesh Eater Courts SC and black knights/ hexwraiths) but am not entirely sure how they will fit together in an army now after reading into allegiances and army comps I might try. Right now I'm thinking of picking up Arkhan the Black and pairing him with a vampire lord on zombie dragon (maybe Neferata down the line)from the SC but neither are part of flesh eaters courts, so if I wanted to use crypt ghouls and vargheists for example, I would lose loyalty bonuses for using units from multiple factions rather than just one from the death allegiance (correct me if I'm wrong I'm very new to this). While I would rather design an army I like playing more so than a competitive one, it makes sense that an army is more enjoyable when the units compliment each other play wise and isn't mish-mash of abilities game play wise. Would there be an way to use ghouls and some of units from the various legions of nagash together in a viable way or am I better off ditching them since they probaby cost me around $5-10 effectively? While I understand that it may not be relevant or necessarily transferable, in Total War: Warhammer II I generally play using meat shield/ defensive frontline units holding the line for monsters supported by magic users to do theirthing (my Favorurite factions are Tomb Kings, Vampire counts and coast, as well as Lizardmen and Skaven).As far as I know death allegiance supports this play style well but I may be wrong and at least I am only $30 in the hole. Any advice or help would be appreciated, this is my first game like of Age of Sigmar so it's a bit difficult to orientate myself with the rules. P.S. Sorry for any formatting issues, my computer is acting bizarrely right now.