Here's the article with the dates for Peter Lomong, brought to the country by Lopez in 2009:
https://www.runnersworld.com/runners-stories/a29337120/lopez-lomong/
As for Rupp, yes, he is incredibly coachable. As far as we know, he would go to the ends of the earth for Salazar and do everything he was ever asked. He is the coach's dream in that sense. That is precisely why there are worries about his being clean. We know the claim that there was a notation about him using testosterone in high school from a doctor's note. Salazar said that was harmless supplement (testoboost?) that contained no testosterone. We know that Salazar's athletes were being injected with over 50 ml per day of a supplement that Magness tried in large quantities and supposedly gave him huge improvements on the treadmill in 2012-13, Rupp's best year+. We know that Rupp had various medications and TUIs over the years. We know that Salazar's athletes were coached to get thyroid medication and asthma medication by running up the stairs before appt's and told what to say, that Salazar self-administered and diagnosed drugs, that he got prescribed testosterone himself and had it available, therefore, to give out, and that Rupp received concealed substances in hollowed out books in London. He did also improve remarkably in a short time. So, there are very strong reasons for suspecting him even beyond all other Salazar athletes. In fact, it was often thought that he of all Salazar's athletes was the one who got everything because he was absolutely loyal and Salazar certainly used him as a guinea pig for everything, while training partners were brought in either as fodder for him in workouts (Puskedra and Levins) or to lead him to greatness (Farah). Crushing Rupp in a workout would get you dropped like that (O'Lionaird, a 3:34.46 guy who dropped a 49 in an NOP workout with Farah and Rupp, possibly in 2012 or 2013? and was quickly gone).
Finally, if it's true that Salazar pushed for Smith to get the Oregon XC job, this has Salazar's fingerprints all over it. Either he directly told Galen to call Smith or Galen remembered Salazar's positive comments about Smith. It is also possible that other coaches turned Rupp down. Smith is a good coach, though, and might in a longer-term situation be able to help keep him healthy because he gets his athletes in great shape without pushing them very hard in workouts, from what I've seen. The long tempos seem to be the hardest things they do. Unlike Salazar, he doesn't give his athletes superman workouts. So, he might help him get healthy. If he were starting with Rupp now, that'd be too soon before trials to do much. If a couple months back, he'll have him ready for trials and ready to run fast by August.