just so we get this clear -- Ashwatthama was NOT a sapta-rishi. He might me in the next manvantara (it's in the Srimad Bhagvatam I believe).
That being said, I'll respect your opinion and your thoughts, but to be very frank - the Pandavas were never favored. The incidents that they had to go through justifies this. Duryodhan was always favored by his blind father and the vows of Bhishma and the debt of Karna and Drona. Vidura was the only one that never "favored" Dury because he saw right through him.
As far as Krishna is concerned, the Pandavas chances were already messed up -- it was 7 to 11 akshauhini with the Kauravas with the larger number hence more warriors. On top of that he had Bhishma, one of the best warriors of his time; Drona - the guru who could not be defeated until he was no longer armed, Kripa - he was immortal, Karna - a fierce and deadly archer, and many other warriors including the Narayani Sena!!! So to think that there is a logical, reasonable dharmic way to defeat Bhishma, Drona, or Karna is kinda silly. If there was a way to defeat them, they would have been defeated a long time ago.
The act of using Shikandini as a shield while attacking Bhishma was deceiving, but there was no other way. Shikandini didn't possess the strength to kill Bhishma, and even if she did, she couldn't do it because Bhishma could die whenever he wanted to!
The Ashwatthama trick was used because there was no other way. Drona alone was more than capable of taking down the Pandavas and his strategy to serve Duryodhan was to make Yuddhi a POW. The consequences of this is astounding because it goes back to the dice game. Yuddhi is a slave, his brothers may be free but they won't disobey him even if he was a slave. IP is totally lost since Yuddhi is a POW.
The marriage of Subhi and Arjun is overstretched in this stupid serial. These two fell in love with each other ... and they did what Krishna and Rukmini did ... so if it's adharma for a couple to elope when one of them was going to be "forced" (since none can oppose Haladhara Balarama) ... then that's a shame.
Karna's kavach was a cheat to begin with. As long as he had that armor he couldn't die. This adds to an above point that again strengthens Dury's army by unfair means.
And that last paragraph is a bit odd. But the particular pastime has been mentioned ...
Anyhow, the bottom line from what I observe is that most of your stuff is from the serial which is sort of unreliable. Of course, I hope I didn't come across as mean or rude or whatever, it's just that whenever someone uses the serial as a reference point, it just hits a bad nerve. So I apologize if this made you sad or anything. 😊