I don't have much to add to many insightful comments in this thread. One of the key factors is the builder on the 11pt.
  White is Player 2
score: 0 pip: 160  Unlimited Game Jacoby Beaver  pip: 159 score: 0
Blue is Player 1  
XGID=bEACAcCaaceB:0:0:1:32:0:0:3:0:10 
Blue to play 32 
1.  Rollout^{1}  7/4 6/4  eq: +0.101 
 Player: Opponent:  52.27% (G:17.05% B:1.08%) 47.73% (G:15.00% B:0.80%)  Conf.: ± 0.003 (+0.098...+0.104)  [59.0%] Duration: 4 hours 04 minutes 

2.  Rollout^{1}  8/5 7/5  eq: +0.101 (0.000) 
 Player: Opponent:  52.05% (G:17.42% B:1.07%) 47.95% (G:14.99% B:0.83%)  Conf.: ± 0.003 (+0.098...+0.103)  [41.0%] Duration: 4 hours 05 minutes 


^{1} 46656 Games rolled with Variance Reduction. Dice Seed: 26996767 Moves: 3ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.10
Move the builder to the 10pt (63D43D32) and making 5pt is clearly best.
  White is Player 2
score: 0 pip: 160  Unlimited Game Jacoby Beaver  pip: 158 score: 0
Blue is Player 1  
XGID=bEACAcCaaceB:0:0:1:32:0:0:3:0:10 
Blue to play 32 
1.  Rollout^{1}  8/5 7/5  eq: +0.113 
 Player: Opponent:  52.29% (G:18.08% B:1.14%) 47.71% (G:15.19% B:0.86%)  Conf.: ± 0.008 (+0.105...+0.121)  [100.0%] Duration: 26 minutes 33 seconds 

2.  Rollout^{1}  7/4 6/4  eq: +0.087 (0.026) 
 Player: Opponent:  51.93% (G:17.10% B:1.09%) 48.07% (G:14.96% B:0.82%)  Conf.: ± 0.008 (+0.079...+0.096)  [0.0%] Duration: 27 minutes 58 seconds 


^{1} 5184 Games rolled with Variance Reduction. Dice Seed: 26996767 Moves: 3ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.10
However, moving the builder further to 9pt (64D43D32) brings the two candidates close together again  I don't have a good explanation for this.
  White is Player 2
score: 0 pip: 160  Unlimited Game Jacoby Beaver  pip: 157 score: 0
Blue is Player 1  
XGID=bEACAcCaaceB:0:0:1:32:0:0:3:0:10 
Blue to play 32 
1.  Rollout^{1}  8/5 7/5  eq: +0.128 
 Player: Opponent:  52.56% (G:18.46% B:1.21%) 47.44% (G:14.86% B:0.85%)  Conf.: ± 0.003 (+0.125...+0.130)  [86.5%] Duration: 3 hours 57 minutes 

2.  Rollout^{1}  7/4 6/4  eq: +0.126 (0.002) 
 Player: Opponent:  52.76% (G:17.80% B:1.16%) 47.24% (G:14.74% B:0.79%)  Conf.: ± 0.003 (+0.123...+0.128)  [13.5%] Duration: 3 hours 55 minutes 


^{1} 46656 Games rolled with Variance Reduction. Dice Seed: 84338134 Moves: 3ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.10
Without an additional builder making the 5pt clearly prevails. (Compare with Nack's variant.)
  White is Player 2
score: 0 pip: 160  Unlimited Game Jacoby Beaver  pip: 161 score: 0
Blue is Player 1  
XGID=bEACcDaaceB:0:0:1:32:0:0:3:0:10 
Blue to play 32 
1.  Rollout^{1}  8/5 7/5  eq: +0.075 
 Player: Opponent:  51.59% (G:16.72% B:0.95%) 48.41% (G:15.41% B:0.78%)  Conf.: ± 0.008 (+0.067...+0.082)  [100.0%] Duration: 27 minutes 55 seconds 

2.  Rollout^{1}  7/4 6/4  eq: +0.041 (0.034) 
 Player: Opponent:  51.09% (G:15.78% B:0.94%) 48.91% (G:15.56% B:0.76%)  Conf.: ± 0.008 (+0.033...+0.049)  [0.0%] Duration: 28 minutes 39 seconds 


^{1} 5184 Games rolled with Variance Reduction. Dice Seed: 26996767 Moves: 3ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.10
Give white her 5pt, and we want to make our own 5pt.
  White is Player 2
score: 0 pip: 155  Unlimited Game Jacoby Beaver  pip: 159 score: 0
Blue is Player 1  
XGID=bEACAcCacdbB:0:0:1:32:0:0:3:0:10 
Blue to play 32 
1.  Rollout^{1}  8/5 7/5  eq: 0.243 
 Player: Opponent:  44.28% (G:14.16% B:0.72%) 55.72% (G:18.84% B:1.20%)  Conf.: ± 0.004 (0.246...0.239)  [100.0%] Duration: 2 hours 00 minute 

2.  Rollout^{1}  7/4 6/4  eq: 0.251 (0.009) 
 Player: Opponent:  44.10% (G:14.14% B:0.71%) 55.90% (G:18.82% B:1.20%)  Conf.: ± 0.004 (0.255...0.248)  [0.0%] Duration: 1 hour 59 minutes 


^{1} 25920 Games rolled with Variance Reduction. Dice Seed: 26996767 Moves: 3ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.10
Finally, when making our 4pt would be correct? Take away one white builder! My take on this is that with only one additional builder white's priming game is weaker and so we can afford to play more flexibly by making the 4pt.
  White is Player 2
score: 0 pip: 163  Unlimited Game Jacoby Beaver  pip: 159 score: 0
Blue is Player 1  
XGID=bEACAdCaceB:0:0:1:32:0:0:3:0:10 
Blue to play 32 
1.  Rollout^{1}  7/4 6/4  eq: +0.195 
 Player: Opponent:  54.34% (G:17.89% B:1.04%) 45.66% (G:13.40% B:0.69%)  Conf.: ± 0.003 (+0.192...+0.199)  [100.0%] Duration: 2 hours 47 minutes 

2.  Rollout^{1}  8/5 7/5  eq: +0.184 (0.011) 
 Player: Opponent:  53.92% (G:18.03% B:1.00%) 46.08% (G:13.47% B:0.69%)  Conf.: ± 0.003 (+0.181...+0.188)  [0.0%] Duration: 2 hours 49 minutes 


^{1} 31104 Games rolled with Variance Reduction. Dice Seed: 26996767 Moves: 3ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.10