You probably mean of a subclade of E-V13 with Poles, Russians, Serbs, Bulgarians etc. on it for a clear Slavic marker?
I wasn't thinking about that and we probably won't find many such branches because simply E-V13 was not an important marker in the proto-Slavs.
When I say migration with the Slavs, I mean a migration with them but not necessarily a Slavic marker.
For example, the migrations in the early Medieval were a big scale migrations, a turbulence that was felt all over the continent and one migration could have ignited many different ones. It was like a domino effect.
So, a tribe of Dacians, Illyrians etc. assimilated into Slavs but not necessarily assimilated and arriving with the Slavs in Greece and the Southern Balkans is not out of place.
And this is not just for clades under CTS9320 but other ones as well.
Look at this one for example:
https://www.yfull.com/tree/E-A18833/
It has three samples, Bosniak at the top of the tree and a Serb and a Bulgarian underneath.
It has a perfect timing with a TMRCA of 1400 ybp.
You want necessarily find northern Slavs in this branch but to me it looks like a clear indication of a migration in that turbulent period into present day Bosnia, Serbia and Bulgaria.
The Italian guy with a star (*) on a parallel branch is from Lodi in Northern Italy and it may look like this branch has to do with the Celts or the Illyrians living close to Italy!