If we play five out the defense doesn't have to come out to guard TJD if they choose not to, and if he doesn't consistently hit the shot, they wouldn't. So the middle would still be clogged up. It's not what you do, it's how you do it ..
If Xavier drives the lane with TJD on the block...there are 2 people occupying that space he's driving in to.
If Xavier drives the lane with TJD on the block, and Race in the other short corner, that's 4 people occupying the area Xavier is driving towards.
Xavier, Rob, Trey, all did a lot of driving into those places...as a result of our offense, those areas were "clogged". And it resulted in less open passing lanes, lesser opportunities for themselves, it even made dumpdowns more difficult.
They didn't ALWAYS run both Race and TJD into the post/short corner areas. There were a ton of possessions where they went high low with one of them at the top of the key, the other on the post. But way more often than not, one of them was occupying one of the block areas, for extended portions of the possession.
Obviously, the thought was our best two players were Race and TJD for most of the season. X didn't fully emerge until later in the year...and when he did, we did a fair bit more pick and roll type stuff, and X's stats and productivity showed. But as you pointed out, we nearly always reverted back to some form of one of the bigs parked on the block when the game came down to the wire, and we needed buckets.
Now...on to what a 5 out offense would look like...assuming both Race and TJD's men do, in fact, sag back.
1. They wouldn't sag all the way into the lane. Defenses don't do that. And that would give Race or TJD an open run to the rim for lobs and stuff. No one plays defense that way.
2. As I mentioned above, Xavier would be driving into an area occupied by probably 1 other defender, assuming Race and TJD are on opposite sides or are spaced away far enough...instead of 2-4 other players. I loved watching Xavier come off ball screens at the end of the year with TJD standing 22 feet from the basket, and Race spaced away opposite. He became basically an All American level PG, stat wise. But he was rarely a "closer" type player at the end of games...my contention is that's because we clogged the lanes back up by parking TJD down low.
3. So, the strength of basically ALL our perimeter players not named Miller...would be catered to, by creating more space in the lane. X, Trey, Tamar, JHS...they're all attacking guards more than they are shooters. Not wide open lanes like you'd get if TJD and Race were good shooters, but for sure more open than last years lane was most of the time.
4. When those players did get into the lane, both TJD and Race are inevitably taught to dive to the rim for dump offs, lobs, or just offensive rebounding. This is how programs like Texas have sent similar guys to TJD in the first round, its what Mark Williams did for Duke, etc...
5. Obviously at any point in time, you can cross screen and roll down into the post, or just flash or duck into the post if you're Race or TJD.
6. All of what I've mentioned above promotes more spacing and player movement. Which would make defenses have to shift and adjust, and would eventually open up areas and spots for shooters like Miller and whoever else emerges as a viable 3pt threat.
7. I don't know where this notion comes from that Miller and Parker passed up a bunch of open looks? Both of those guys are gunners. They passed up shots because they had people close enough to them to chase them off the 3 point line, more often than not. And that's because teams realized they didn't need to double Race or TJD much to limit their efficiency. Most teams made it pretty easy for us to dump the ball down to either of them. Not much fronting. Very little doubling. Its almost like they welcomed us dumping it down there? Hmmm?
In the end...it for sure isn't perfect. TJD and Race not being willing and/or able to hit outside shots does make pretty much any offense we run less versatile, and ultimately less effective. We aren't going to have a top 10 offense next year no matter what we do. But we could have a top 10 defense...and a top 40 offense. I just don't think we can get that top 40-50 offense with anything resembling what we ran most of the season last year.