Standard machine empires don't have to worry about food or consumer good production, so you need to factor that in. They need to be build and maintained by robots with their already fairly high maintenance costs. It is much, much higher than just 2 energy. The Coordinator job worries about far less variables and production pipelines than organic pets need to.
Napkin math suggests that, On day 1, assuming everything is planet-based, you need 17 energy for all the building and 'bot upkeeps, as well as 3 districts for mining and farming, two buildings slots for the bio-trophy home and civilian industries, plus 8 housing (or two additional housing) for the machine pops themselves. This will give you the food and minerals needed to supply the needs of 10 bio-trophies for 20 unity, with an excess of 4 minerals, 2 food and 2 consumer goods.
Uplink node for other machine empires takes one building slot, 9 total energy, 2 additional housing and produces 6 unity and 6 society research.
Comparing only Energy-unity, RS creates ~1.17 unity for every point of energy, while other Machine Empires produce .67 unity per point of energy. This is actually an improvement of about 75% from the normal ME for the Rogue Servitor.
It is also more building efficient at 10 unity per building slot vs. 6 unity per building. Districts are a probably the closest metric though, if we take all the generator districts needed to power all this (keeping in mind generator districts only have a net gain for ME of 5 energy, thanks to the district upkeep of 1EC and the 2EC upkeep for the pops) and round up to the next whole district it's 7 districts for 20 unity vs. 8 districts for 22, or 2.86 unity per district vs. 2.75. However, one must also keep in mind that, while the mining districts used might have otherwise been used for alloy production, that agri district would otherwise remain unused and frees up a generator district whose EC can be used to support more Machine Pops.
So, by all three metrics, Rogue Servitors are more effective at generating unity than their Machine Empire peers. Are there more moving parts involved? Of course. But extra logistics is a deal breaker for you, well... I guess that's why you picked Machine Empires in the first place