Many found it strange that the Esocline Federation would be willing to go so far as to serve as an external strategic deterrent for the sake of protecting the Kandrian Empire. Perhaps if the Kandrian Empire and Esocline Federation had been age-old allies with a long history of cooperating with each other, it would make more sense.
However, that most certainly wasn't the case.
If anything, the Esocline Federation was closer to being an ally with the Sekigahara Confederate due to the fact that it had been the supplier of esoteric military technology to the Sekigaharans.
The Sekigahara Confederate did not conduct any R&D when it came to technology. They had no background in it and were strictly Martial. If not for the fact that being deprived of such military technological assets would have made them the weakest of the four Sage-level powerhouses of East Panama, they would have never bothered getting their hands on such technological capital in the first place.