If you don’t know, unlike previously CMC of split cards is now the sum of the two parts. This was done due to the abuses on older split cards with cards like As Foretold and the different Expertises (mostly Kari Zev’s Expertise). On the other hand, there are cards that like your cards being expensive.
There’s two split cards in Amonkhet that seem strong here.
The manabase definitely sucks and would require some work. Actually a lot of work.