I disagree. There's really nothing to fear from Lurch Manning. He got his neckbolts adjusted and is a year out of football. Reports are that he has lost velocity on his passes. Manning is a my-way guy offensively so he'll further screw up the coaching mess in Miami or NYJ - one HC brand new after the incumbent was fired and the other on the hot seat.
Good news for us: it'll be a sideshow to have Manning come to town once a year and it's unlikely he finishes up next season anyway.
Adding him and his mega-salary to Miami or the Jets will only make them older and less flexible to bring in additional talent.
Manning in Miami could rekindle a bit of a rivalry with those guys and if he's any good, could further marginalize the Jets. All good.
The Jets, on the other hand, are in cap hades as it is, paying Manning north of $20 million will further diminish their ability to be competitive now or in the future. Even more fun, Manning on the Jets will be a QB controversy from day one. Those teams always implode.
There are lots of reasons to welcome him to the AFC East.