The likely results of races between these 4 depend on the circumstances.
Are we talking just the 4 of them in the races? Have they got a single pace maker? Are they in a championship environment with 4, 7 other runners?
In the 400m, it doesn't really matter which of the above scenarios is used.
In his prime (1981) Coe ran a 45.6 relay leg from a stumbling start and 90 mins after solo running a 1:44.0 800m. He was clearly capable of sub 46 that night in an open race. Ovett in 78-80 could probably have run close to 47.0 (46.8 relay in 79). Rupp would be 3rd and Pre 4th, both a long way back; which isn't surprising, since they are both distance runners and the Brits are middle distance guys!
People say that Ovett would have a good chance over Coe in the 800 based on a 2-1 winning head to head. Well the first clash in 78, Ovett was probably at his prime (I tend to think he maintained a pretty equivalent peak from 78-80). Coe was only 21 and certainly not the finished article. In Moscow he ran a diabolical tactical race, yet was faster than Ovett in the closing stages, given he had to run a lot further on the 2nd lap to pass guys on both bends. Coe proved in 81 with his WR and solo 1:44.0 (12.3 last 100m) that he would have beaten Ovett most of the time, barring accidents, in his prime. Having blown it in Moscow, I find it very hard to even consider he'd run like that again over Ovett, as seen a week later in the 1500. So, Coe 1st, Ovett 2nd, Rupp 3rd and Pre 4th.
At 1500 I'd plump for Coe again. He showed in his practically solo Stockholm run of 3:31 in 81, that he was capable of running and winning from the front in a 3.75 lap race, even off a suicidally fast opening 2 laps. I just don't see Ovett being capable of replicating that. If it was a slower tactical race, then the chances of Ovett taking advantage of bad tactics increases, as does his chance of winning. If Coe is within 3m of Ovett with 200 to go, I think Coe would still win, whatever the pace. Rupp would come 3rd & Pre 4th.
At 3000m it gets a lot closer and more interesting. If there is a rabbit and/or a fast race with a field more than just the 4 of them, then on paper it looks as if Rupp would be capable of running the fastest. If it is slower (7:37 -7:45) then Ovett's kick could get him past Rupp in the closing stages. Ovett looked very easy when beating Rono & setting the then 2 mile WR of 8:13.5 in 78. That was equivalent to c. 7:41 for 3k, and I'd say he could have run 4-6 secs faster that night.
Coe shouldn't be discounted at this distance either. He had exceptional endurance capabilities for (primarily) an 800 runner, something which many don't realise or choose to ignore. He only ran one 2000m in his career (4:58.85 in early 1982 after coming back from a foot injury, and running alone for the last 3.5 laps) and one 5000m, 14:06 in May '80 when winning the Yorkshire Championships by 200m in what was basically a training run! Just because he had a 7:54 3000m that doesn't mean that was all he was capable of! He ran a handful of indoor 3000m on the appalling wooden 200m track at Cosford as training runs. When he ran that 7:54 in March the last km was 2:30, and it was probably worth a good 5 secs faster on a decent 400 track.
Coe also beat Coghlan (83 World 5000m Champion) and McCloud (10000m Olympic silver medalist) in a 4 Mile road race (17:55) in Ireland at the end of '78; beating the then World record holder at 3000m and 2 miles, Brendan Foster's course record by 9 seconds; off a season running only 800m races! Both Coghlan & Mcloud had run 13.20 that previous season.
Coe also won the famous Vigevano road race twice (7.5km) in 1980 & 1983, recording 18.28 for the 6.7km; 27:33 pace for 10,000m). In the former he easily beat Cova.
So in a 7:30 race I think Rupp would edge it, but if it drifted to 7:36 or slower, the I think Coe or Ovett could have a chance of winning.
Over 5000m then Rupp should win in a fast race, but again if it drifts to 13:10 - 13:30 then Pre comes into contention as well as the 2 Brits.
Ovett was capable of 13:10 in 86, when way past his prime. Back in 80 I think he could have run faster in the right race. I think Coe's potential at 5000 was equally as good as Ovett's, and Frank Horwill (the chief National middle distance coach in UK during the 80's) agreed.
" I went to Battersea Park Track one Saturday morning with a 13:11 5K performer (Tim Hutchings) to do a session of 7 x 800 at 5K speed with 45secs rest. The rep times were fixed at 2mins.08secs because the 5K runner was returning to fitness after injury. Coe was on the track and came across and asked what we were doing and could he join in? I felt a little apprehensive that an acknowledged 800/1500m runner would not survive a 5K pace session with a short recovery. The 800s went like this: 2:08, 2:06, 2:04, 2:02, 2:00, 1:58 and 1:56! Coe led them all. Afterwards, he confessed that he did a 5K pace session at 13:20 speed each week. I ventured the opinion that he could run a good 5K anytime. He agreed, but said he didn't like the event!
Over 10000m, then Rupp & Pre would be quite some way ahead of the other 2, who both finish in around 28mins.