This season seems to be really bad for the Arrowverse writers. They can't seem to write an episode without the characters being morons in order to advance the plot. I get that characters make sub-optimal choices in the interest of character or even ham-handed drama, but it's getting really bad.
Their plan was to let Zoom into Earth-1 and then use the anti-speedster gun on him. No backup plan. I'm stunned that Wells went along with this. The speed gun should have been followed up with a pummelling/speed draining nanites/tranquilizers IMMEDIATELY until Jay was positively restrained and couldn't have been playing possum.
Then, Then!, they honour the deal with Zoom?!?!
Couldn't they have played possum, pretended that Barry was out of speed force? Even started a new fight with Barry and Zoom to get him back through the portal into Earth-2 when Wally was safe?
I'm stunned that Wells didn't have some "defence-in-depth" going on. ie. What if Barry's primary plan doesn't work? Apparently, the fallback position to that was... nothing.
I expect this kind of stupidity from Legends.
Don't get me started on the time remnant. When did he come from? How did Zoom convince Remmy to allow Zoom to kill him? All the experiences with Caitlin were with Remmy, right? Why does Zoom even listen to her in her appeal to humanity? Basically, they've never interacted.
If they're going to make a season spanning villain, they need to actually plan it out so it makes sense in hindsight.