Grant is right, sorry King.
TJ Zeuch probably does suck but he's worth keeping around as a depth SP while he still has options (unless he gets bumped off the roster by better players) and there is a chance that he ends up as a useful SP. I believe he has a better minor league ERA than many of Toronto's young SP depth (Thornton, Kay, Hatch, Waguespack). Minor league ERA is dumb to look at in almost every instance but maybe not when you are trying to evaluate a guy with a stupid/weird profile like Zeuch. He's completely outside the mold of current analytic trends and he's a weird player because it's probably SP or bust - hard to imagine him as a useful reliever - and in the current game backend SPs who chew up mediocre innings are not coveted.
The type of player who, if the team gets into SP injury trouble, could end up supplying ~15 not terrible starts in a season.
Grant's ceiling comps are generally too sexy but here is a more fitting one: https://www.fangraphs.com/players/aaron-cook/1571/stats?position=P
Toronto should have traded Zeuch for David Dahl!!! why the f*** did that not happen