Actually:
McMillan calculations have Rupp (13:07) @ 7:31.3.
If you compare to someone with similar times (Henry Rono),
27:22.47,13:06.20, 7:32.1 - it's entirely possible for Rupp to run around 7:32 @ Rieti based on his most recent performance (13:07). Rupp's strong point is actually his speed - but he never gets the chance to use it at the end of a fast 5k/10k because he lacks the strength. The 3k, in my opinion, is more speed and lesser endurance when compared to 5k and then 10k.
I think Solinsky might struggle more than Lagat - eventhough their PRs are only about one second apart. I see Solinsky as a more pure strength runner and not necessarily a blazer. Rupp could take him in a mile or something shorter.
This is assuming there is a commitment to the pace from start to finish - no waddling. You just can't close in 53-54 when you've already run more than a few laps @ 58-60 (with one or two disastrous 63-64s).