I'm not hindered by any form of musical knowledge, just a music lover.
Is someone a hitchhiker on the succes of others when he makes a mash up of those 2 songs, yes.
Or is he a genius when he mashes 2 songs which have no significance what so ever.
99,5% is of the first category, 0,5% the latter
Off all the mash up's that i heard the best one is a not a hardstyle/hardcore mash.
It's Enter Aretha by Rolf Schraa, the ultimate mix of 2 different styles.
Music and lyrics of Metallica, voice by Aretha Franklin, the ultimate souldiva.
(a rather poor example given the state of Enter Sandman.....)