I am unfamiliar with Historic (it looks like just another WotC EDH
clone going back farther than Brawl?), but I did build my partner a very successful Kinnan deck for regular EDH. Taking a look at your list, I think you're missing the point of Kinnan a bit. Cheating out creatures is cool, but Kinnan's biggest strength is the ability to ramp, HARD. You have basically nothing on the lower end of your curve and almost all of your mana production is through lands.
Why are things like
Llanowar Elves,
Arcane Signet, and other cheap nonland mana generators in the sideboard?
Arcane Signet with Kinnan out is 2 mana for 2 mana, so basically free.
Mox Amber is 2 mana for nothing, so a better
Sol Ring with Kinnan out. The great thing about Kinnan (unlike Mayael, who Kinnan essentially replaced) is that you don't
have to cheat out something big. As long as Kinnan is the only human in the deck, you can use the ability on
any creature you flip. Sometimes, flipping a
Priest of Titania will help you more than some 5/5.
I would strongly recommend going back to the beginning and aiming for a lower curve. Having 10-20 cheap (CMC < 3) sources of nonland mana will make your mana production spiral out of control. Someone stealing
Nyxbloom Ancient doesn't matter if you can make 30 mana per turn without it.
For your big creatures, it's important to have a good number in Kinnan, but you only really want enough to guarantee flipping one most of the time. An occasional whiff is acceptable, but at least 80% of the time or so you want to be able to cheat in something terrifying. I settled around 15 big bois, but most of them were game winning (things like
Blightsteel Colossus,
Vorinclex, Voice of Hunger, or
Ulamog the Infinite Gyre).
tl;dr: More mana dorks/rocks, lower curve, fewer big bois.