Firstly the Army that attacked Hussein RA:
الإرشاد للمفيد ج: / 95
“And they reached thirty thousand on that day, So Amr bin al Hajjaj was given command of the right side of the army, and Shimr bin thu al Jawshan took the left side, The one who was leading the riders was ‘Azrah bin Qays, The one who was leading the foot soldiers was Shibth bin Rab’ee.”
source: Al Irshad by shia scholar al Mufid 2/97.
Now who were some of the people who wrote to Hussein RA so that he might come to kufah and be their Imam:
المفيد في الإِرشاد ج2 ص37
“Then al Shibth bin Rab’ee, Hijar bin Abjar, Yazid bin al Harith bin Ruwaym, ‘Azrah bin Qays, Amr bin al Hajjaj al Zubaydi, Muhammad bin Umayr al Tamimi they wrote: “The fruits have become ripe for cutting so come to us and you will find a huge army waiting, peace”.
المصدر \راجع الإرشاد : 2 / 36 – 37.
“From those who wrote to him were Habib bin Muzahir, Muslim bin Awsajah, Suleiman bin Surd, Rifa’ah bin Shaddad, al Museeb bin Najbah, Shibth bin Rab’ee, Hijar bin Abjar, Yazid bin al Harith bin Riwaym, ‘Azarah bin Qays, Amr bin al Hajjaj, Muhammad bin Umayr and their likes”
source: Al Irshad by al Mufid 2/36-37.
Then you have al Shirm, who was he?
“Shirm bin Thu al Jawshan was amongst the supporters of The Caliph Ali PBUH in the battle of Siffin.”
Shia sources: Safeenat al bihar by Sheikh al-Tusi 4/3. Bab al Sheen Ba’ad al Meem p492.
المصدر/ في رحاب ائمة اهل البيت(ع) ج 1 ص 9السيد محسن الامين الحسيني العاملي
“This Zhr bin Qays had witnessed the battle of JAMAL and SIFFIN alongside Ameer al Mumineen Ali PBUH as well as al-Shibth bin Rab’ee and Shimr bin thu al Jawshan al Dababi then they fought against al Hussein PBUH on the day of Karbala so they had a horrible ending and we seek refuge in Allah from such an ending”.
source: Fi Rihab AhlulBayt 1/9 by Al Sayyed Muhsin al Ameen al Husseini al Amili.
So who were the Men that lead the army against Hussein RA?
1- Amro bin Sa’ad.
2- Shim bin thu al Jawshan who led the left side. (was a Shia who fought under Caliph Ali RA in Siffin).
3- Amr bin al Hajjaj who leads the right side. ( wrote to Hussein RA telling him to come to kufah )
4- ‘Azarah bin Qays leader of the riders. ( wrote to Hussein RA telling him to come to kufah )
5- Shibth bin Rab’ee leader of the foot soldiers. ( wrote to Hussein RA telling him to come to kufah )
The one to expose them was their own imam al Hussein RA who called the leaders of this army (All Shia) by their names and told them:
! الارشاد ج2 ص 98
“O Shibth bin Rab’ee, O Hijar bin Abjar, O Qays bin al Asha’ath, O Yazid bin al Harith didn’t you write to me that the fruits had become ripe for cutting and that I come to you and find a huge army to support me?”
source: Al Irshad by al Mufid 2/98.