Why they need Tor when they (will) have Pantsir ?
Very different systems, despite competing range bracket.
First of all, Tor was available much earlier, so inspired copying could begin also way earlier. Furthermore, Pantsir is, in essense, super-CIWS.
It isn't true SAM in capabilities, it's meant to cheaply proceed multiple targets coming at it or in it's direct vicinity.
Note when it shoots at the outer limit of it's range, against even against slow targets flying by, but doing evasive maneuvers - it misses, because missile is already "dead" and can barely maneuver.
In comparison, Tor is true short range SAM (in HQ-17A form, with seeker, not even that short anymore!). It's missile can engage targets with designed probability of kill(pK) even at the outer edge of it's range bubble, even if it performs radical evasive maneuvers throughout entire engagement loop. It's very, very hard to kinematically beat it. Plus warhead is quite significant there.