Having finally gotten to watch the original Japanese version of Armada just last year, I finally have a better grasp on what the show was trying to do with its particular depiction of Megatron, which got lost or at least obscured in the English dub.
See, we know Beast Wars Megatron. He acts like he's high class, talks like a sophisticated intellectual with a dash of hamminess. Bob Forward even once confirmed that they basically cribbed Megatron's personality wholecloth from the character of Patrician from the Discworld series by Terry Pratchett.
By having David Kaye do a variation of his Beast Wars Megatron voice for Armada Megatron, it was like trying to fit a square peg into a round hole, because in the original Japanese version, Armada Megatron is neither classy nor a sophisticated intellectual. He's instead more like a barbarian warlord. A brutish tyrant with a bit of Viking or even Klingon influence in him. He's all about power and strength, might make right, and believes only he should have all the power for himself. He talks a good talk, but it's all boasting and bravado, not wit or manipulation (that was more Thrust's role).
Using David Kaye's Megatron voice for that kind of character just feels really jarring, when he's trying to sound like a civilized individual but having to say and do such brutish things and don't jibe with the voice at all.
