The four schools of thought are not a sect. they are schools based on Fiqh differences and not in Aqeedah.

The 73 sects have different Aqeedah and some of the followers of the 4 schools of thought can be one of them if their aqeedah is corrupt.

According TO AN AL-HADITH,BEFORE THE DAY OF JUDGEMENT THERE WILL BE 72 GROUPS IN ISLAM….AND AMONG THOSE ONLY ONE WILL GO TO JANNAH…I WANT TO ASK THAT IF THE GROUPS FOLLOWING FOUR IMAMS WILL ALSO BE A PART IN THOSE 72 GROUPS?