The idea is good, i love sieghorn but never played him. I think you're lacking a few things one of the is
Savage Stomp it's an important card in a dynossaurs deck specially in this subtype of
enrage.
Another creature that you're lacking is Deathgorge Scavanger cause he can give you life and
exile creatures from you're opponents graveyard, i'm talking for example Phoenix or the Eternelize guys.
I have tried the deck but i dont know how easily you can get city's
blessing so you can you propery Wayward.
I would try to use maybe 3 seal aways and 1/2 Settle, and maybe 1
Ixalan's Binding in mainboard.