It really comes down to whether or not you think its best to have an enabler or a payoff as your commander, since Szarekh mills you while Imotekh rewards you for getting stuff out of your graveyard once its milled
This is because it is a purposive card, you can put it in a deck and improve that deck with no prior knowledge of your opponents deck or who is on the play
It adds first strike, plus the potential to free-cast more expensive cards if you can stockpile extra energy before playing it
Erayo, Soratami Ascendant / Erayos Essence Heres another from the cool flip condition collection, Erayo, Soratami Ascendant
Which makes sense: why play one of the best Pokmon cards out there when you could play two of them
So its no surprise that Robin Hood, Champion of Sherwood is relatively expensive even as a non-Enchanted card