Not really the same logic but I see the link you're making. For one, third round picks aren't expected to be starters when they come in. Second, I'm not certain that this team would have drafted Cooper Dejean, but did need a DE, and Sweat is worth that pick. Third, that line about the thirty-second pick is tiresome, but notice that right now the team knows what slot this third round pick is now.
Here, you are getting a pass rusher that would come in and start, who has put up double digit sacks in this league and who does deserve a pretty penny in return. You are getting it with a pick that could legitimately go to DE, and you are getting one that you can count on being better than a rookie. That's a targeted investment, and one I think you can be more confident than one is in Claypool, and is far cheaper than the price to bring in Sweat. You can't build a team that way, but you can bring in an important role player or two that way