LogFAQs > #976503065

I'll answer purely on your Ray Stevenson comment... basically copying Leon.

Ray Stevenson is the start of the show. He was an unknown to me I've absolutely been loving his portrayal here, I really wasn't expecting such an interesting character out of him and finishing the show made me deeply sad to lose him as an actor.

As for Clone Wars / Rebels... there's maybe like 3 key details that could help or provide an impact to the series (not that that's the extent of references, but meaningful things to understand). Basically the concept of who exactly Ahsoka is which you may or may not already know, the ending scene of Rebels (what it means for where Ezra & Thrawn are), and maaaybe the Clone Wars Mortis arc although that last one isn't the most direct relevance bit at least of yet.

Definitely one more thing I can think of but that's probably a bit more work to contextualize and I mean it wouldn't really be that out-of-place to witness it for the first time through the Ahsoka series. It calls back to Rebel's incredible season 2 finale though... but watching that wouldn't be enough which is what I mean by "more work". It's probably more of a reason to be interested in Rebels than something actually needed to understand Ahsoka. Actually this goes for the Mortis bit too.

Also if you like Thrawn in Rebels clips, he's very much the exact same as Rebels portrayed him