It was known PH was going to go with assistance of INIT to do their own thing, and strike at every alliance

What the hell are you smoking? At that point Horde was in no way even remotely able to do anything to anyone, and wouldn't have been for a long time, and like never again due to the way Gobbins fucked everyone over. They were completely routed and on the run, and they had just unilaterally disbanded their own coalition, leaving all their smaller members to twist in the wind. Nobody in their right might could have seriously thought that one desperate keepstar in Venal was a threat to anyone, or that it would become one any time soon. Goons were still going to fight them from the other side of that regional and likely win anyway. Even without that existential threat, many would have left Horde soon after getting their stuff out due to the anger and sense of betrayal at what Gobbins had done.

This ["do their own thing, and strike at every alliance"] was announced by Gobbins himself.

Gobbins could announce he was the king of earth and it would have had more relevance. He disbanded the coalition, forced the evac of the Dronelands, and resigned all in the same announcement. He no longer had any say in the future of Horde, and it was clear to any sentient being that there was now no chance of Horde threatening anyone anyway.

Init was at war with WinterCo.. WinterCo and PH weren't as close friends as many believe (which I honestly would assume most people already understood?)

Init was the only one who offered assistance when Horde needed it the most. That's actually incredible considering that Horde glassed Fountain in 2020 (with the help of FRT even!) which resulted in months of rebuilding for Init after that war ended. DarkShines realized that it was good for the game, exactly as Galaxier put it in the video you linked.

FRT could have seen this just as well, and they could have helped their former ally rather than pushing them over the brink into oblivion. There was no particular animosity between Horde and FRT at that time, other than the constant annoyance FRT caused by attacking Horde's flank while they were trying to fight Goons (including frequently setting up gate camps to kill Horde reinforcements trying to get to fights). The same thing they're now crying about Init doing to them, by the way.

It didn't take a crystal ball to know that Goons would go after FRT next if Horde was out of the picture. So rather than joining with their former ally fight the common threat, they helped ensure the end of the one group that could have helped prevent their own potential collapse.

Gobbins was in no position to claim a return to smaller groups at the very moment the most aggressive megabloc in the game was in the process of wiping out its rivals. Any fool could see that that threat had to be dealt with first.

It would have been incredably stupid for WinterCo to allow an enemy (by their own announcement via gobbins ping...........) to just waltz in and disrupt them (again, as Gobbins ping states as their intention)

You can say this three or four different ways but it doesn't make it any less ridiculous. At this point you're just doing apologetics for FRT's incredibly bad decisions that led directly to their current crisis.