27,705 might vs. 23,067. for the loss.
Learn team compositions. Watch the replay carefully and you'll know why you lost.
When using crit heroes there is a chance you will loose. I seed demon hunter solo a whole team. Ultimate after ultimate he bursted me down with even 3 level difference, blue versus gold ... That very lucky random luckstream when he crits all the time. You will never be able to report a RNG related issue.
First of all, might doesn't matter that much when you factor in hero compositions and counters. You have to counter the enemy not just by sheer might but how your heroes work well together to defeat enemy teams.
There is also random crits which can wipe your team. I have a feeling that your Prima Donna died to the enemy demon/scarlet combo while the enemy was able to heal at least 1 time to kill your team.