J-20 further along development than PAK-FA?

This out of Janes

I have always assumed the Pak-fa flew a year earlier than J-20 and there are only 3 Pak-fa prototypes and 2 J-20 but this news from Janes seems to indicate there are not just 2 but up to 4 models, which also indicates that perhaps the J-20 program is actually further along.. perhaps its true first flight date being earlier than the first Pak-fa flight?

i would not put it past China as they are known to be secretive and play with timing.