The difference with getting Seymour is he was in his prime and still is. It was worth it. I truly believe if you ask BB what his greatest mistake was he would answer trading Seymour. It set his defense back so much and it probably cost them a championship between then and now.
With Palmer it is a gamble. He is coming to a 3-2 team that probably has the ability to win the division. But this isn't some running back that you can just drop in and tell him hit the hole and hit it hard. This is the QB. He has to lead, he has to learn the system, and he has to do something I am sure Palmer hasn't done since retiring...study tape. If this was the off season I would say he'd be in a great position to succeed. But a 1/4 of the season is gone. How much is he really expected to contribute being thrust into the proverbial fire?