in the case of clay I think that was the weathers conditions of that year in 2009 in where roland garros was faster similar with the year of that agassi won rg too.
but I think that federer with fast courts in this era I mean after 2008 , the guy would win more.
but if roger played with players like in the 90s . the things would be more balance
That was not the point of the comment about whether Federer would do better in a different era considering he started before homogenisation.
The point is very clear and simple, that apart from movement there is so little difference between the surface speeds therefore it much easier for them to be breaking the records they did which is exactly what Federer was saying.