Well I have recently been playing Total War Saga: Britannia and Total War: Attila, and I like them a lot. They are my first Total War games but I enjoy them but I think they’d be harder for people to get into than Paradox games in my opinion if they normally don’t like these types of games. They are a bit more involved in the strategy part.
Rambling of a tired person lol
Opinion of Brittania
My honest first impressions of Britannia were not so great because they do not teach you how to play the game, they just throw you into the deep end. They give you informative hints on pieces of the mechanics, but not how to actually play, if that makes sense?
For example, it will tell you what a character’s trait is, but not how to move your armies, raise levies, build things, discuss diplomatic things with other countries etc. It leaves you completely in the dark, assuming you have had years of experience with Total War. Even then, if you read the reviews, the majority of people’s complaints seem to stem from the fact that the game itself has shifted rather dramatically from prior games (such as requiring a food supply for your levies and need to slowly raise levies). There’s also the saddening reality that they left out full mod support out of Britannia, meaning no overhauls, just simply texture redos and simple script changes.
Beyond that, the aesthetics are astounding. The sounds, the graphics, the soundtrack, the artwork, the cultures and units and most of all, how the battles play out. It is incredible to zoom in while your warriors hack apart your enemies and take wonderful screenshots of the surrounding terrain, like forest and fields.
Overall, I was having fun when I began to understand it, but I felt frustrated that they did not try to teach people. They shouldn’t assume everyone buying is a 5+ year veteran of the series. Couple that with the purposely mod decline, I say Britannia is something you definitely pick up on a sale. Something like $20 is very fair. Nothing more than $23 is fair unless they do some serious amount of patching.
As for Total War: Attila (I have Charlemagne + Vikings DLC because I am a fanatic for Scandinavian stuff), I honestly enjoy it more. It might sound strange to complain about for a game, but Attila holds your hand a bit more in the start by explaining how to play. Britannia doesn’t do that. Attila also has full mod support, incredible battle mechanics (my first battle was a dual battle, of naval and ground forces, it was epic!), great graphics, incredible music, engaging naval and ground battles, easy to use, follow and enjoyable diplomatic screen, a better tactical map, a far larger campaign map (Britannia is restricted to, well, just Britannia), and way less bugs due to extensive years of patching.
I bought it for $11 and I think it is well worth the price, though I hear from my friends that “Rome II and Medieval Definite Edition are the most incredible games ever made”, so there’s that. 
I’m not sure what to say beyond how I feel about the game and what it offers and doesn’t offer, but I do know that if you’re into strategy games like Stellaris or CK2 only, where there’s equal varying degrees of strategy and character (player) interaction, then maybe more Paradox games are what you might be interested in. If you are into strategy games, especially engaging ones where you can control an entire field and the armies on them (even naval), including features you commonly find in Paradox games, then you might enjoy the more popular Total War titles like Warhammer 1/2, Attila, Rome II and Medieval, but pick them up on a sale.
So far though, I definitely suggest to people who are interested in picking up suggestions of others, to check out Total War: Attila. I think it is great.
I will have an opinion on Warhammer II soon, but honestly, I’ll probably like it. 
