Perimeter defense?
Yeah it was bad, but it was not the biggest weakness....
We didn't have enough scorers...plain and simple...
outside of Roy, there was NO ONE else who was a consistent 2nd, let alone 3rd scoring option for POR...Aldridge showed up for abput 1/2 the games to fill that #2 scoring role....Rudy had 1 game in a loss that he showed up...NO OTHER PLAYER could be relied on to score for POR in the HOU series...and THAT is the #1 problem with this team...not enough scoring....
Now you could be myopic and "hopeful" that guys like Rudy, Oden, Bayless, Webster or Outlaw

develop into that 3rd guy...which may or may not happen....
OR you could take this ONE TIME OPPORTUNITY and use some of your cap space (cap space\opportunity that you will not have again for a long time) and over abundant but underdeveloped assets (young players\draft picks) and go and get that 3rd scoring option to compliment Roy and LA...and THEN if another guy does develop...be it Oden, Rudy, Bayless...then you can be in a VERY good position to make some serious NBA title runs....
Turkoglu isn't perfect...he isn't my first choice even...but he is a good player and he would be the 3rd scoring option on this team...and THAT is what POR needs first and foremost....
I agree, perimeter defense sucks...Sergio is not very good, Blake is underwhelming at best and Bayless is an unknown with potential....but adding another defender into the starting 5 doesn't help solve the #1 issue (scoring) that is the achilles heel in the playoffs for this team....
POR needs to address that shortfall first...