how do you deny a connection between bossy and bovis on the one hand and yet make PIE connections that are so non-obvious (ox, bull, cow)?

I don't think I denied a connection between English boss(y) and Latin bōs. (In fact, I stated that some think that boss(y) was borrowed directly from Latin bōs.) I was implying that English boss(y) did not go back to Ancient Greek bous. (If anything, the two words are cousins of a sort, because they all go back to PIE *gwous.) If Early Modern English boss(y) could be tracked back to Classical Greek, you would have to explain why you were redrawing the family tree of IE languages. How was it that Greeks migrated to the area around present-day Jutland and how their speech was transformed from something quite different than surrounding Germanic languages into something that does not look like Greek, but remarkably looks like those same Germanic languages. Then you have to explain how Old English cy, which is related to Greek bous, came to be, while boss didn't go through some similar sound change. By this time you've pretty much left linguistics, lexicography, and etymology far behind and travelled to a foreign land. Perhaps I don't understand your statement.

Ceci n'est pas un seing.