Leshy is the ex-god of chaos, so it’s no surprise he favors chaos and that it guides most of his actions, which also makes his motives pretty unpredictable, even to the other Bishops.
Hating the Lamb would be the logical thing to do, but approaching them in a friendly way will result in more confusion and a chance to annoy the hell out of Narinder as a bonus.
So far Lamb doesn’t seem to mind, aside from the confusion the interactions cause them.