Wlad needs more 'body of work' to assess his ability to beat Larry Holmes. Holmes was a great fighter who snatched his victories of out several certain defeats, remember when he was decked by murderous Earnie Shavers and came back and KO'd Shavers or his close win over Ken Norton.
I believe if Wlad consoladates the Heavywieght title and does it impressively, then I will consider Wlad being favored over Holmes. At this point I just don't know.
Regarding Cooney, Wlad would demolish him. Cooney was weak mentally. Once the fight got past six rounds and Wlad was still on his feet, Cooney would panic and tire. Once Wlad would see this, the end would come shortly thereafter.