The test is to remove the other person from the sentence see see if it still makes sense:
Me and Sumo together got it => me got it (wrong)
Sumo and I together got it => I got it (right)
It was got by Sumo and me => it was got by me (right)
It was got by Sumo and I => it was got by I (wrong)
The test is to remove the other person from the sentence see see if it still makes sense:
Me and Sumo together got it => me got it (wrong)
Sumo and I together got it => I got it (right)
It was got by Sumo and me => it was got by me (right)
It was got by Sumo and I => it was got by I (wrong)
In summary; leave Sumo behind next time.