The Browns are crap, and will be crap for a long time. But this move makes sense. They just flip him to another team as a backup and eat maybe 6 mil of his salary and get another draft pick.
So they upgraded 2 draft picks and get another for about 6 mil. They have tons of cap space, and a huge part of it must be spent this year or there are penalties.
However, they will use all the picks to draft alcoholics, pot heads and/or shitty players so it wont matter much.