I like this trade, but for those who don't, consider the NFL window factor.
Now that the NFL window has been reinstated, regardless of the fact that it wasn't in effect when Manziel signed his contract, do people not think Manziel's agent will do everything he can to get Manziel out of his 2019 CFL obligations? Even if the team/league took a firm position on enforcing the terms of the original contract, the past negotiations between Manziel's agent and the Ticats, and prospect of a big fat commission from an NFL deal suggest a high probability of holdout/lawsuit/arbitration/etc. Further factor in that the current CBA is set to expire before the 2019 season begins, which could throw more wrinkles into a saga like this.
James Wilder Jr. and Victor Butler may not have got the result they were hoping for when they rocked the contract boat this past off-season, but based on what we saw in the leadup to this season, and especially with the NFL window returning, I wouldn't be at all surprised if Manziel's agent tries his damndest to get Manziel out of the CFL once 2018 is done.