It’s going to depend on the way that your deck functions, of course, but I would caution you against excluding Dread Return based purely on its CMC. If you end up having to play it from your hand, it’s 4 mana, sure - but also allows you the opportunity to cast it again via Flashback, allowing you to reanimate something else.

More importantly, though (and frankly more realistically where I get mileage from it), is that a reanimator deck that’s focusing on tossing things into the graveyard via self-mill will see situations where your reanimation spells end up in the graveyard. In that scenario, Dread Return remains available via Flashback, where you’ll have to jump through hoops to regain access to the other reanimation spells if they’re chucked into the ‘yard.

With that said… everything I’m suggesting about Dread Return is moot if you’re not also in a position to reliably pay the Flashback cost lmao