Three problems usually attach to "stretch 4's".
1) they are perimeter pansies. No guts. No inside play. They practically squeal at the first sign of physical contact, and faint at a bruise. Hence they run away and hide out where the big meanies won't hurt them.
2) for many of the same reasons, as well as their position on the floor, they are useless as rebounders, which is a core PF trait. Your center is stuck doing all the work inside on the boards, and even if he is a great rebounder, you as a team may suck because he has no wingman.
3) for many of the same reasons, many stretch 4s are poor defenisve players, especially against physical power players.
So now let's look at "Pat Pat":
1) his background is not born and bred tutu wearing weenie. Its as a fairly tough college PF. And he actually has some post game, at least at the same level as a JT. He's just too small and weak to use it consistently. But thing is, we have Cousins. So the normal problem of your team getting too perimeter oriented with a stretch 4 is not so much for us. You can really only play one post player inside at a time anyway (I still remember Dale Brown's attempt to run a double low post system with Stanley Roberts on one block, and Shaquille O'Neal on the other -- it was great fun, but also highly messy). And with the right matchup, Patterson is not so much of a weenie he doesn't know how to post a guy up.
2) rebounding. a Huge HUGE issue for a terrible boarding team like ourselves. We can't afford to get any worse, indeed need to get better. But here's some intersting numbers. First, Pat Pat's per36 rebounding numbers:
Yr 1: 8.3
Yr 2: 6.9
Yr 3: Hou: 6.5
Yr 3: Sac: 7.9
And then JT's rebs/36:
Yr 1: 9.5
Yr 2: 9.7
Yr 3: 9.4
Yr 4: 9.6
Yr 5: 8.5
what you get there is this: during Patterson's rookie year he was on the level of barely acceptable, but then fell off the last 2 to being simply not a starter level. Meanwhile, Jason was very consistent as a good but not great rebounder in his first 4 years, but this year he has fallen off badly, and since coming over Patterson has improved enough that he is rebounding in the same general range as JT this year. Now neither guy is rebounding well enough to get us out of the rebounding doldrums, but at least iin deciding between the 2, Patterson has been better than normal, and JT worse, and now the gap is much smaller that it was last year when it would have almost decided the question itself. No idea if that will last, but its critical.
3) defense. I've seen Patterson get bounced in there by power, but aside from that he's felt like he generally knows what he's doing, and his block numbers per minute (a poor proxy in this case, but it is what it is) have bounced back a little like his rebounding has thus far with us. It should be noted that most Houston fans will tell you he was a lousy defender for them there, so it might just be a case of another team's lousy defender lookng like gold to us because they don't know what lousy defenders really are on the level we do.