Vishy was outstanding middle order for 70s, a border line ATG, whose stats would never tell how good and elegant batsman he was. Two things went against him - 1. he never cashed on easy money like his bro in law did, hence his average stuck at early 40s & 2. His conversion rate was extremely poor for a batsman of his calibre - only 12 tons in ~91 Tests and one double. But, he had some of the most crucial 75+ in Indian Test history and he raised his game under pressure. Playing for a weak Indian side for his entire career, he never lost a Test when passed 100 & that 114 @ MCG will be regarded as one of the greatest innings played by an Indian in Australia. As a Test batsman, I rate Vishy slightly above Zaheer because of his back-foot play; both were outstanding spin players, supreme stylish but GR Vishy was better against raw pace & bounce - in ODI, absolutely no comparison though, Z was in different cloud, several level above. Along with Atherton, Kim Hughes & Majid Khan, Vishy was another one who was far better player than his stats. He won’t make the starting XI of 1970s Test team, but I’ll take him in 15 men squad.
Dulip Vengsarkar was a typical Bombay batsman - methodical, doing correct things often and hungry to be in middle. He wasn’t the talented batsman like GR Vishy, but he put value to his wicket and made his starts count. For 2-3 years in mid 1980s, he was indeed among top 2-3 batsmen of world and Marshall rated him as his most priced wicket for some times, but I don’t think DV was a better player than say Salim Malik. I saw him on his last leg - still compact, methodical but just not the batsman you could expect greatness, he would find a way to get out. He was made Captain after Kapil, probably at a wrong time to lead an weak Indian team which cost his batting big time, still he has left enough legacy to make Indian second XI.
Jimmy Amarnath is probably the freakiest batsmen in history - for a period of two years, between 1982-83, what he did itself was probably enough for a borderline ATG status, and he would have done great had he retired after 1983 WC to preserve his legacy - it was down slide all through there after, which saw him being dropped against same WIN team 18 months later after scoring 1 run in SIX innings, at home; then he wasn’t even called against PAK, a team against whom, 2 years back he almost alone protected 5/6-0 sweep, fighting a lone battle against a rampant Imran. Overall, Amarnath was a fantastic utility player, but I don’t think he will be remembered long for his Test heroics, rather for the MoM of 1983 Final. His achievements in 1982-83 winter (& spring) season is probably very similar to Wasim Raza or Peter Willy against Lloyd’s team. Jimmy was our first professional coach, at his peak, a die hard fighter, but I won’t put him among great batsmen - I would rather say, he was a bit lucky that at his peak couple of years, he had lots of games to play, including a WC and to his credit, he made absolute use of that.