Who do you count then? Without Udina, then I can only count Anderson and Hackett. The game only has 2 prominent roles then.The game doesn't have that many high ranking humans in the first place. Strictly military then I guess Ashley. That's 2-1. I don't think the ratio is that bad then.
I'm not talking strictly military. Look at my first post, I'm talking mostly talking about people like Anderson, Udina, TIM and Hackett.
Even if I was talking military, I don't think Ash and Kaidan really count. Their role in the game is essentially to follow orders not give them, and they're not Admirals. At best they'd command a ship, not a fleet.
Let me try a list, though odds are I'll forget someone particularly among the minor characters
Military
Men:
Admiral Hackett
Admiral Anderson
Admiral Kahoku (minor)
Admiral Mikhailovich (minor)
General Petrovsky (Cerberus)
(unnamed Admiral who get blown up)
(other unnamed admiral who gets blown up)
Women:
Admiral Hannah Shepard (minor, might not exist)
(Unnamed Admiral who gets blown up)
Civilian
Men:
TIM
Udina
President Huerta (offscreen)
Ambassador Osoba (minor)
Women:
(Ambassador who doesn't appear in the games and so I don't know the name of)
Things get a lot better if you step a rank or two down below "flag rank" or equivalent, I'm not going to deny that. Ashley, Miranda, Kahlee Sanders, Captain Riley, Doctor Chakwas, various senior mercs and security guards like Matsuo and Jedore etc etc. But there's a sense of a glass ceiling being there, because of the make up of the very top.