Neither Noteboom nor Allen has any guaranteed money left on their contract so in this case trading them wouldn't help. (If they did have any guaranteed money the Rams would have to eat it if they cut them, but their new team would pay it if they were traded.)
One problem with Noteboom, though: he is due a roster bonus of $5M on March 18 and if he is still on the team then they have to pay that. He has to be off the team one way or the other prior to that date otherwise there would be no cap relief whether they cut him or traded him.
AlbaNY_Ram