regarding the drummers who just hammer away with their arm on their hi hat, i think sometimes it's a conscious choice to achieve a more consistent sound for each hit as opposed to accenting the strong beats. i'm a drummer and i can play Moeller style but for certain things i intenionally play with more arm to get that really rockin constant driving feel. but i think this can still be accomplished with mostly wrist usually and some drummers take it too far, either for a performance effect or just lack of technical knowledge
let's say the notes are going by at 4x 80bpm. so 16th notes at 80bpm, or 8th notes at 160 bpm. ..... does that change things