No quality size outside of KG.
Please check out every roster on the NBA team. How many have more quality than Bass, Sullinger and Wilcox supporting up their best big?
Indiana has David West, Ian Mahimi and Hansborough.
Chicago has Boozer, Gibson and Mohammed.
San Antonio has Diaw, Splitter, Blair and Bonner.
Miami has Rashard Lewis, Udonis Haslem and Joel Anthony. Lakers have Pau Gasol, Jordan Hill and Jamison. Atlanta
Horford, Pachulia and Ivan Johnson?
Knicks are rolling out Stoudemire, Thomas, Camby and Sheed.
Philly has Spencer Hawes, Lavoy Allen and Kwame Brown.
The nets have Kris Humphries, Andray Blatche and a couple of struggling Euros.
Orlando is bringing Vucevic, Ayon and Nicholson.
Honestly how many 7fts do you see in the bunch? MOST of these guys are Sullinger's (and Bass') height with less bulk.
How many of these guys have more athleticism than Jared Sullinger? Bass and Wilcox might be the most athletic of the bunch. How many of these guys rebound and block shots better than Bass and Sullinger? Not close to as many as people make out. Our Bigs are perfectly fine above average in fact.
On your list, West, Boozer (not so much anymore, but still better than Bass/Sully), Pau and Horford are major impact players that outstrip the impact of any of our non-KG bigs.
Guys like Splitter, Gibson and Hawes are more useful too.
Bass and maybe Sully qualify as above average back-up 4s in the right situation, but we don't have an above-average starting 4 or an above-average back-up 5 to keep them in their ideal role. And further, our one elite big man can't play much more than 30mpg.
Thus our bigs are only really good when they play with KG.
West is slightly better than Bass and earns a lot more. The other guys are 2nd or 3rd best players on their teams who make 2-3 times as much as Bass. Splitter Gibson and Hawes are NOT more useful. Gibson and Splitter have no offense. Hawes is a poor defender. If you want to pay two hall of famers, a dominant point guard, deep bench, and still want a Horford or Gasol then you're building an All-Star team not an NBA team.
That's kind of like Laker fans saying their weakness is they don't have Iggy instead of Peace, or Heat fans saying their weakness is not having Cp3 instead of Chalmers. No one will be complaining about our size when we play to our full potential. We have enough to win 18.
I think there may be some optimism bias here.
Our PG is 3-6th in the league or so. Very good, but with flaws, and unfortunately his flaws may not mesh well with the team flaws.
SG is a solid notch above replacement level, but probably low-average starter (until Bradley comes back and ONLY IF Bradley plays this whole season as well as he ended last year).
SF is a future hall of famer, but he's definitely on the downslope. Still all-star level, but not all-nba any team level.
PF is either rookie or Bass. Good Bench PF/Sub average starter.
C is KG. Out of position? Future hall of famer for sure, but noticeably down a couple notches from what earned him the hall. Very good D. Really regressing on offense. Like Pierce, still all-star level, but not all-nba.
Bench: Terry should be a solid mle bench player. Green is overpaid and unless he does something he has never shown in his career, will be overpaid for his career. some big bodies with big flaws.
I don't think it's unreasonable to think this team could (or should have) rework some assets to get a real starting center, and bring sully/bass as bench bigs. We certainly aren't a juggernaut at this point.