I appreciate the effort you put into this weighting system but there is no way Lendl ranks above Sampras, Borg and Nadal.
In assessing a player's legacy, Masters series count for far less than slams. The ATP has to assign points to them for the ranking system but that doesn't mean that they are half as important as slams, i.e. a guy who wins 2 Masters series events is not as great as a guy who wins 1 slam, and the history books will certainly not remember him in the same way.
Sloane Stephens and Laura Robson: future WTA world No 1 and 2.