Imran had 6 centuries while Kallis only had 5 five-wicket-hauls ( 2 were against BD and the horrendous WI team ). Imran's batting is far superior to Kallis' bowling in Test cricket. I agree he is not an ATG batsman and #6 where he generally batted, required him to face both the old and new ball. Test cricket is all about discipline with the ability to score runs at a consistent rate. When Imran batted, a run rate of 3 was standard and 4 was splendid. Nowadays, a run rate of 4+ is generally expected from top teams. Imran executed his role to perfection as far as batting is concerned. Imran's ability with the ball is unquestioned as evident by his 23 wickets in the 87 tour of the WI team at the fag end of his career. Although Sachin broke every record for a batsman, he is not remembered as a match-winner. In fact, if you wanted someone to bat and chase 300+ on Day 5, most people would choose Lara over Sachin. Sachin failed when it mattered the most ( 03' Final, 11 Final, 09' CT ) and most of his centuries in WC's were against weak teams like Kenya, Namibia. His only noteworthy centuries came against SL, ENG, and SA which were all lost or tied. IK meanwhile averaged 35 with the bat and 19 with the ball making 1 century against SL which won the match for his team. Despite not having a 5-wicket-hual in the WC, the two teams he did have 4-wickets against ( WI and ENG ), his team won the match. Not only is Imran a greater match-winner and cricketer in Test but also in the World Cup which is the benchmark for ODI cricket.
It is difficult to juxtapose a century and a 5 wicket haul because a direct comparison is complicated to establish. The reason why I compared these two is because fans of both players overhype their secondary skills. Neither Imran's batting nor Kallis' bowling were up to the standards of specialists.
No player in history has ticked all the boxes, and neither has Tendulkar. However, there is not a single batsman who ticks more boxes than Tendulkar. No player has achieved more over the course of his career, but yes the failures in World Cup finals count against him. Had he scored in either of the two finals, I think he would have finished his career as the number one ODI batsman of all time ahead of Viv, but that did not happen. I would probably put at him number 3 after Viv and Kohli.
Nonetheless, Tendulkar was an excellent World Cup player overall who played some clutch innings, and his contribution as a player in the 2011 World Cup was more significant than the contribution of Imran in the 1992 World Cup. He was the second highest scorer and had scored almost 100 runs more than the next Indian, while Imran was finished as a bowler by that time and played only one meaningful innings (the final), and his innings in the semifinal was no better than Misbah's Mohali, but Inzamam and Miandad saved the day for him.
Still, performance in a World Cup final counts a lot which is why Imran's contribution in the 1992 World Cup is remembered fondly not only as a captain but also as a player. Nonetheless, over the course of their ODI careers, Tendulkar is well ahead of Imran.
For pretty much 80% of his career, Tendulkar was the best ODI batsman in the world, while Imran was below Kapil in ODIs almost his entire career who won India a World Cup 9 years before Imran could, with a weaker team against arguably the strongest team of all time. In addition, Imran couldn't match his explosive batting.
Furthermore, all this talk of Tendulkar not being a match-winner is largely a PP myth. Yes he was not a match-winner in the same mould as someone like Viv or Kohli, but he has won India many games and is greatly regarded for carrying India on his back for years before the likes of Dravid, Ganguly etc. emerged and shouldered the burden.
Lara was better on day 5 pitches, but he also better at going for selfish big scores at the expense of the team and he was also a tail-ender in India, while Sachin has excelled in every country he has played in. Speaking of day 5 performances, his hundred against England in Chennai 2008 to chase down 380 is one of the best fourth innings performances of the last 20 years.
Scoring on day 5 to win or save a match is good, but if you can consistently score in the first or second innings then you will probably not need to play stonewall innings on day 5. I would rather have a batsman who can consistently score in the first or second innings rather than a fourth innings specialist.
Tendulkar is a much greater player than Imran in ODIs and in Tests it is very close. However, overall, Sachin is ahead of Imran. Imran is certainly the greatest Test all-rounder from Asia, but as I said earlier, a comparison between a specialist batsman or bowler and a specialist all-rounder is illogical to begin with, but Tendulkar has achieved more as a batsman than Imran has as an all-rounder, is why he makes more all-time XIs than Imran, who rarely makes an all-time XI because he was inferior to Sobers.