This murder never made any sense. i mean Testa was Scarfo's most loyal guys who also was a top hitman and earner. It wasn't like he was under investigation like roy demeo was where ther was a chance he would talk
While I agree with you for the most part I'm going to play the devils advocate. Look at how the 2 bosses before Scarfo died. I think he dreaded Salvie marrying Chuckie's daughter as the potential Merlino/Testa alliance would be a threat to his leadership and when Salvie broke it off Scarfo decided to take him out so the problem couldn't arise again. After all, ambitious underlings were what got the 2 previous bosses killed.
