Wrong. 2500 years is the I2a1b-Din TMRCA, from the diversity of Poland-Ukraine.
You are wrong, you speculate, even you didn't read (or understood) what I wrote.
I didn't speak neither about TMRCA nor about several TMRCA methods which can give different results.
Very precise, you can read what I wrote:
1. I-CTS10228 formed before 5300 years.
TRUE or FALSE
2. Nobody knows where I-CTS10228 formed (5300 years ago)
TRUE or FALSE
You "know" it is Poland. No, you can be badly mistaken.
What we have for now, two samples who classified as I-CTS10228*
One is from Poland and other is from Alsace (border area between France and Germany). Nobody can know where third sample can be found.
3. What about time difference between 5300 years and TMRCA 2300 years, it is: 3000 years.
TRUE or FALSE
Maybe someone thinks I-CTS10228 was under glass bell 3000 years and jumped.
But things don't function so.
We don't know neither what's happened nor about territory movement, of course we can speculate, for example about bottleneck and reasons for it.
...
I-CTS10228 has older brother it is I-FGC20479 formed 5300 years ago, found on British isles.
If we investigate movements of haplogroup I-P37 formed 21200 years ago we can see wider areas of Europe, including Balkans, Eastern Europe, Western Europe etc.
I-P37 is Paleolithic European haplogroup, very old in Europe.
Many thousand years after, first Neolitic farmers entered in Europe (G2a, C1) and more later E-V13 etc.
...
This is an overview, and without of speculation.