I would agree that Beast,Oak and Erebus should be considered tier 1 Demigods, not because they are always better choices than other demigods but because they will always be a strong choice to play regardless of the situation.
I definitly wouldnt consider Regulus as a bottom demigod though. IMO ignoring the whole general vs assassin minion issue, all demigods are competitive EXCEPT FOR QoT.
Again this might just be because of my demigod of choice and playstyle but when I play against a QoT I just rack it up to an easy win, even if my opponent is breakin an 80% win record. At best I see QoT as an early game threat, which at worst means just play defense and dont let her bust down your towers early game.
So its possible with a premade team strategy you could go for an early game victory, but since IMO thats her only viable route its easy to defend against.
I never had much luck as QoT myself either and dont enjoy general builds as they take too much "thinking and work" IMO. Ive played with some real good QoT players but Ive yet to face an actual QoT build that I would consider powerful.
Its hilarious to me that starcdock or whomever is in charge of balancing has let QoT be relatively gimp this whole time I just have assumed that they know something I dont know about QoT but Im starting to really doubt that.