In 3 grows I had this happen twice.
Once from Peakseeds C99 and now from Critical Mass.
There is another thread here on the board on the subject.
These twins seem to appear more and more as time goes on (probably some effect on the gene pool of cannabis over the years of breeding).
Anyway, long story short:
Most likely they are 2 identical plants and if you don't remove one of them, they will both grow and mature with one just remaining smaller than the other.
For me that's what I ended up with
geometry dash
I would rather remove the small one and top the bigger one for additional colas. From my (limited) experience, it seems "better" than leaving them both to grow in the same pot. Just gonna end up with 2 identical plants where one is considerably smaller/behind and overall lower yield than if you grew out 1 and topped it.
Just my 2 cents.