Schweini is not a top player, but a very good player still.
Him prefering
Arda over him is simple Andy, its all about watching Schweini for years and knowing he isnt awesome but a quite good player. While Arda is a player he hardly seen except couple of times, not enough to notice his limits and flaws like a player you seen for years, but is promising enough that unknown quality about him (of basically not seeing him) makes your image of the player seem like he can be awesome.
They are in a different stage, when it comes to how people can view you as a player, the latter has the luxury of hype to ride on and the what if side to it that paints a prettier picture then he prolly is, its easy ones mind skips from a talent to a big talent when the factor of the unknown is in play ( you get predictions "can bloom on to a super star" without showing much yet, before you to play and dissapoint these exaggerated predictions).
While in the case of the former, you pretty much know what you will get after years of being in top level football, you have gauged his strenghts and limits and know most of it (has not the luxury anymore to be perceived as someone that can "bloom into a superstar" because he already passed that stage when he was younger).
This may not entirely be the case for this KhalidKassim poster, but nontheless dont ever understimate the power of imagination