It depends what POD, you are using losing at Okehazama it gives Yoshimoto a chance to become Shogun or try to control it, but by 1560 he is dealing with the Miyoshi Clan at its hight and a steady but powerful Mori clan. There still the Iga Ikki and Ikko Ikki, what happens with the Takeda and Hojo. In theory, an Imagawa Shogun could be much different than the Tokugawa it would be founded on a position of strength and legitimacy unlike the Tokugawa for the latter and the Toyotomi for the former. I have my own take on this POD for a timeline, but I've admittedly taken some liberties.
Then again if Yoshimoto does become Shogun I would expect the Mori to continue dominating in the West, The Chosokabe securing Shikoku, maybe even the Shimazu uniting of all Kyushu. Eastward it is hard to say the Takeda could still become a regional power along with the Hojo, however, what happens between them and the Imagawa could go a different way, as it unsure how their triple alliance with each other and the Imagawa was going to play out if Yoshimoto is not dead. For Central Japan, you can expect more of stalemate as the Miyoshi slides into irrelevance and infighting, and the Ikko-Ikki remain strong.
Anything that could result in a mutual kill of both men could see the Takeda poised to control Central Japan, the Matsudaira/Tokugawa risk being isolated, as Nobunaga's young son Kimyomaru would require a reagent, and might not be able to support them in their independence.