I don't know about the future, but it's been working pretty darn good so far in the present.
At least with Jeff Green with them.
So far this season, including last night's game against the Spurs (which dropped these numbers just slightly) when Green, Sully & Olynyk have been on the floor together:
ORtg: 103.3 (points per 100 possessions)
DRtg: 99.4
An interesting point is also to note that when Kelly plays with others (i.e. Green & Sully both on the bench) the DRtg leaps to 109.5 points per 100 possessions while the ORtg drops slightly to 101.6.
But it is also interesting to note that when Green & Sully play together, but without Sunshine, THEIR numbers are worse as well! ORtg: 100.2, DRtg 102.9.
So, basically, these three have performed very well as a front court threesome.