Everyone agrees January transfers are required, for lots of reasons.
Lets however be realistic who will come to the Spl ?
The league is one where prospect players use to get to the English Premiership.
So if you are, for example playing for Leicester, would coming to Celtic improve your chances. Also the likes of Duffy and Phillips have not shone when they have been on loan to Celtic. So its a bit of a risk.
I cant think of an established player who will transfer to Celtic ( or Rangers) maybe you can?
Just because Br wants 4 or 5 players ready to start playing its going to be difficult to lure them to Celtic in Jan without european competition