Not that any of you want to hear it, but I am in full agreement with DaddyO and others who have said let the three guys fight it out for SS... and let them continue to do that until the others give up or force you to do something different. If Mariner management believes that 27 games is enough to force there decision making process... I better become a Cubs fan again.
Furthermore, it needs to be acknowledged that Miller is not the sharpest tool in the shed, and I question how much actual baseball sense he has... but he is a passionate athlete who likes to compete... and he has MLB baseball skills... and I do not EVER remember any time he has complained about anything. Disappointment yes, but no malice.
My gut tells me that the likely outcome for the three man competition turns into Miller as the left handed offensive SS, Taylor as the right handed speed and defense SS, and Marte as a catch all the rest and lead off man / no power guy. If this is the case, then my opinion is Miller should be playing 40 to 50% at SS, 20% in the OF, and the rest on the bench. Taylor would play 40 to 50% at SS, 15% or so fill in for Seager / Cano on days off, and the rest of the time coming in as a defensive replacement at SS. Finally, Marte is either in Tacoma or playing OF 60% of the time leading off if successful doing so, with 10+% of the time at SS.
While I agree there is a chemistry between Cano and Marte, I fail to see how that helps the 2016 Mariners currently.
Again, I would definitely have the competition first.