Even Sue has all mental skills at Mediocre. So a mental track of 2. In addition, zombies are typically nameless NPCs unless you raise someone like Sue so no conditions for them. Third, your own control roll for the spell isn't going to be mediocre. You are definitely going to generate some extra shifts from your control roll since we're using Combat rules and an Evocation instead of a ritual. And last, the chance that the zombie rolls a +4 is 1/256 so out of 256 zombies, you are going to have one uncontrolled. I don't think that's a problem
So, if you roll just enough and don't generate any extra shifts, you need 7 to bind a common zombie mook, 5 or less to summon it, +2 to zone the effect. That's 10 shifts, tag the "nearby corpses" aspect because the spell needs dead bodies and the "contituous drumbeat" aspect because you usually need the drumbeat (or simply spend a Fate point) and you do it on the entire zone.
To control zombies equivalent to secondary NPCs, you need +6 shifts to your spell to bind them. (they resist up to moderate consequence)
To control Sue the Zombie Tyrannosaurus, you need another +16 shifts because she has full consequences and needs a better contacts roll. That's a total spell of 36 shifts which will be a ritual unless you are a big-ass 30 refresh necromancer. (7 skill, 6 focus, 5 specialization, 1 necromancy, 3 Lawbreaker, 2 tagged aspects, 10 mental stress and 10 backlash)