I'll do it
Ken Barrington–Rahul Dravid
Dravid: 9,000 runs @ 53
Barrington: 11,000 runs @ 55
I think Dravid would debut much earlier than Barrington, Barrington largely managed to dodge the 50s, Dravid won't do that and would have a much longer and healthier career than Barrington, Dravid would be terrific in England as he always was, abroad I actually think he would perform better than Barrington in South Africa because South Africa that Barrington toured had the flattest Cricket series ever in their history, with the first few pitches being turners, Saffer spinners won't manage to challenge Dravid on those and as the people said back then, the attack wasn't the right type for those wickets.
I actually think Barrington would get to play in 1990s even as an inferior young bat, he was by all accounts very entertaining to watch at the time and it's not like India were blessed with a great non-Dravid number 3, seeing how much VVS played I think he'd play quite a bit in the 90s as a mid 30 averaging bat, in the 2000s and after his stylistic change mainly he would probably average north of 60, would end as a rival to Sanga and wrap around 2009/10 after a 14 or so year career.
Fred Trueman–Dale Steyn
Trueman: 550 wickets @ 24
Steyn: 400 wickets @ 21
Fred was fitter than Steyn so would play and bowl more, and we know his level away from home on roads against top class batting to be around 26~, home conditions are also pace friendly so record won't change too much, one point at most. No Virtue Signaling bullcrap where he can't bowl short to some old guy, he won't be dropped because I doubt Cricket South Africa cares too much about the person's nature, would have the career he probably deserved rather than being shafted for all the overseas tours until the flat 60s.
Steyn I reckon would play less as the healthcare for pacers was even worse back then and very little even managed to have careers, he would match Fred's home record but I think he would be picked for the uber spicy 1954-55 Ashes, Steyn won't get in as much trouble as Trueman I reckon, who broke George Headley's hand with a good length ball and a big reason for him being shafted was his angry young man attitude, he would play that tour and would go to South Africa, would end with a much more balanced away record that I think Trueman would've ended with if he got all the tours.
Viv Richards–Everton Weekes
Viv: 7,000 runs @ 55
Weekes: 6,500 runs @ 52
Viv would have a longer career, he probably plays well into the 60s, I don't think Viv was as good as Weekes when it came to just ruthlessly attacking weak bowling or plundering on flat pitches but Viv would end with a much better record in England and Australia, the 1957 England series and 1951-52 Australia series would be much different now because it would be Viv vs two ATG attacks, I reckon he would average 50 in both Australia and England, play like 10 games in Australia and 14 in England, Trueman vs Viv would be legendary and they'd face four times I reckon, would average 50+ against both Australia and England. Viv and Sobers would be some partnership.
Weekes would actually get rest when he's injured, would retire sometime around 1986, would absolutely murder India anyway, would kill anyone at home other than like 1986 Pakistan, won't have the same ATG tours away from home that Viv did and I reckon he would struggle in Pakistan greatly in 1980 and 1986 but think he'd make lots of runs in England, Australia is a toss up, I think he'd do well in 1975-76 and 1979 but not Viv tier, he'd fail in 1982, he'd feast on the weakened bowling in 1984, overall he'd be good away but definitely not as well as Viv, would still be easily the best batsman of the West Indies but not quite in Viv's class.
Sunil Gavaskar–Geoffrey Boycott
Gavaskar: 10,000 @ 50
Boycott: 8,500 @ 50
They already almost entirely overlap in career, Gavaksar retired a couple years or so after Boycott IIRC, so I think they'd do roughly the same when you account for it being more difficult to bat in England in general, I think Boycott averaged more than 70 against spin too and was experienced on wet pitches so I think overall he'd do very well, he didn't milk lineups as well as Gavaskar and the deciding factor between them has always been the fact that Gavaskar was somewhat better at attacking and scoring on easier wickets
Alastair Cook–Graham Gooch
Cook:7,000 @ 40
Gooch: 14,000 @ 47
Cook would still retire early, but I generally think he was slightly better than Gooch against spin and stump to stump slow swing bowling, would feast in India and Pakistan flatties unless Imran pulls an Imran, In any case, he'd have to play a lot against West Indies and Cook was very good but I can't see him averaging more than 30, especially against Garner, he was very bad at getting on top of extra bounce and I think he'd face hell, I think he'd score heavily Against Australia in 1986 Ashes though, overall he'd be very good but I think Gower would be regarded as better.
Gooch would probably have a long, long career, he would retire properly in the bazball era, flatness of pitches at both ends of his career would make his stats better, his peak would be even more glorious and I think considering how flat Australia was in 2010 and 2017, how good Gooch was against Johnson type bowlers and prime Gooch would make runs even in 2021 Ashes, I think overall he would excorcise the Australia demon in the absence of Terry Aldermann, retires as a complete legend after 2023 Ashes which I think we win with a Gooch class opener instead of the two we had back then, but maybe not if he's post prime. He'd be the English captain for literal ages, a much better one than Root and Cook. Would be a far better ODI and T20 batsman too.