I made 3 modpacks on my server. Despite lowering mod quantity and giving more ram TPS behave the same. Everytime if there is more than 2 players tps drops to 10-15. Here is my recent mods. I think it's a entity problem and untamed wilds or alexmobs are causing it.
https://docs.google.com/spreadsheets/d/19PLKwRUSVtldyvzims1vjMKj9wUyp6ZdxwZDly5FaW4/edit#gid=0