Well the actual numbers are without any guess of vgchartz for GT is:
http://www.polyphony.co.jp/english/list.html
9.190 + 5.350 for GT5P. 2006 PS3 was released. 2008 GT5P and 2010 GT5. Total is 14.54 already.
Many people say that is basically 1 game. I can see them releasing another GT game with install base.
I do not think all Forza games put together make that numbers. Vgcharts do guess work and the numbers are probably much higher than it should. They often do such things on many games to get reaction, traffic on the site. Some of their guess, estimate are probably closer than actual numbers !?
At the rate Forza goes I think Forza 7 might release before GT7. But I am not sure that will make difference. GT is by a long shot pinnacle of racing sim on consoles. However they need to know what other game devs are doing. TBH they really do not care about other racing games and just do their own thing which can be frustrating for people waiting and waiting for GT game and that causes disappointment as well.
Forza gets good ratings and that probably helps it but otherwise is no where near GT.
