Gokulacandra's "Yogabhyasa" and liquid

Gokulacandra released an album early this year (15feb 2015 according to Itunes) named "Yogabhyasa" and with some fresh tunes (but not so famous I think..).

And this is what I observed :

Mage (0:00 -> 0:05) (out 6 april 2015) :

The sampling is quite obvious (0:00 - > 0:05) (out on youtube the 5 dec 2014):

Same for ActRaiser (2:10) (out 13 april 2015):

Sampling this (0:00 -> 0:07) (out on youtube the 1 dec 2014)

The purpose here is not to spark a controversy, but I am just wondering, is this normal ? Or fair ?

The samples that Mage and ActRaiser are using is not everywhere in their sound, and music is a lot about sampling, but imo sampling a track that is out for 10-20 years is ok but not tracks from the year just before..

Maybe this sounds were sampled by Gokulacandra from another music, I don't know..