I got to thinking about how Zurg is involved in the first few eps of the show (The Torque Armada, XL, Gravitina, Little Secrets) but weirdly not in a direct way, instead getting other people to do his dirty work (for example, nabbing a random biker thug lol), and I have a theory about why.
Obviously, out of universe the reason is that the show is establishing its rogues gallery, but I think you can make sense of it in universe too.
Basically, Zurg is still recovering from the events of TAB. That seems to have been his biggest scheme to date, he probably threw a lot of resources into it, he attacked what was presumably an important Galactic Alliance planet to steal the Uni-mind which almost forced a full-scale confrontation with Star Command (something I get the feeling both sides are wary of since they're pretty evenly matched), and he might still face retaliation from them for that and for everything else he did, plus his number one agent has been arrested, his tower is a wreck, and Star Command even occupied Planet Z briefly after he escaped in the Dreadnought (presumably he drove them off again, but who knows what kind of damage they did while they were there).
So while he's building his power base back up, he messes around with smaller-scale schemes that are very low risk for him because he's not directly involved, and that also don't require tons of resources. NOS-4-A2 was probably him testing the waters once his forces had recovered with something a bit more intense while still not being entirely hands-on in case it went south, and then Planet Destroyer is when he actually gets 100% back in the swing of things. From then on, most of his schemes are much larger in scale and he's usually actively involved (for example, Lost in Time, Rookie of the Year, Stress Test, Super Nova, The Lightyear Factor, Star Smasher, etc. which all have him striking directly at the Galactic Alliance in a very visible way).
There isn't really any kind of repeat of the first few eps where he's just roping in other people to do all the work, so imo it makes a lot of sense if that was just an interim measure while his empire recovered.
