Title says everything. The post in question.
/u/Gankom left a post in the same thread linking a post by /u/Total_Markage that might give more context to the Mongol forays into Poland and Hungary in addition to siege tactics.
https://www.reddit.com/r/AskHistorians/comments/f6vqce/how_did_the_mongols_manage_to_win_sieges_so/