Question:
Why do we only have one minyan after shabbos and holidays? Why don't we have a bunch like we have the rest of the week? And why do we do it immediately after the holiday ends?
Answer:
Thank you for your question.
There is no problem with having numerous minyanim at different times after Shabbos or Yom Tov. The reason your shul doesn't do it is most probably because everyone wants to daven at the same time. In the shul I daven in there are 6 to 7 scheduled minyanim.
Best wishes