I might be mistaken but wasn't Kincaid also known as Drakul's Hell hound? I'm thinking that Kemmler would have treaded carefully around Drakul, but planned on defeating him after a successful Dark Hallow because as you say, he wouldn't want to share.
Kincaid was his Hell Hound yeah. Ebenezar confirms it in Blood Rites, and he's called it by the Denarians.
Yeah I think Kemmlerites the Necromancers Acolytes/Disciples using and playing each other during Dead Beat they probably learned from their Master's tactics.
Whatever the case Kemmler and Drakul would have had to have been aware of each other.
The fact that Drakul is still around would suggest he played it better, albeit with the loss of a powerful Black Court.
Even that could be considered an advantageous outcome from a certain point of view. If the Black Court were becoming too much of a threat.
Nicodemus considered weakening Polonious Tessa's faction of the Denarians a beneficial outcome in Small Favour. Drakul might think along similar lines.