Honestly, the issue is less the Scarab itself, and more that you have a high redundancy of minions that are super slow. Dioltas and Healer are both functionally the same kind of play (except, Healer does have provoke, which is somewhat relevant.) Decks like these are super dependent on having fast plays (spells with legs,) like Sunset Paragon, Primus Fist, Dancing Blades etc.
I like @raqyee’s suggestion, but I’d rather try something like…
-2 Repulsor Beast
-1 Dominate Will
+1 Entropic Decay
+1 Dancing Blades
+2 Sillhouette Tracer
+2 Primus Fist
+2 Rasha’s Curse
In general, the idea is to increase the number of fast plays available to you, and shift the tech around. Sillhouette Tracer is a better defensive choice than Repulsor Beast, because repositioning your General tends to make you harder to reach, or allows you to plow down something with your face that your opponent is trying to protect- where Repulsor Beast lets you invalidate something slow for a couple of turns (but as Control Sajj, you tend to want to clutch the board center, reducing the amount of time you buy with Repulsor.) Your curve also shifts upward a little, making Spelljammer more awkward than options like Sojourner, Flood, or Ruby Rifter. Decay works remarkably as a singleton. Rasha’s Curse is just super flexible.
The biggest mistake I’ve seen with Scarabs is trying to go all in on getting the blast value. Scarab is one of (if not) Vet’s best dispel sponge- and while it’s tempting to try and protect it for blast value, it’s fine to play Scarab exposed/semi-exposed on one of the non-center board tiles.Trying to put it on the back row means stepping away from the center of the board, and letting your opponent establish range that might become problematic. Scarab’s raw body can do most of the heavy lifting, and often just blasting down a column is strong because your opponent will be playing against the ankh by spreading out on the rows.