I've done some research, but I'll do some more later.
But from what I have gleaned, the Krath are descendants of Empress Teta, the same Empress that helped the Republic beat Naga Sadow. Their fleet is actually quite remarkable, as are their warriors. Maybe the Mando's win off of their numbers, but the Krath have been outnumbered before and been victorious. So maybe the Mando's can win, but not at the cost of a good majority of their ships.
Not only that, but both the Krath and Massassi have bested the Jedi Order in battle. The Jedi that they beat would school the Mandalorians in a battle, so Kun has the obvious land advantage.
On the topic of Basilisk War Droids. The war droid was only available to Mandalorians of the highest standing. their "nobility", so to speak. So I doubt a quarter of the Mandalorians have a Basilisk War Droid.
Known in the Mandalorian language of Mando'a as bes'uliike, or "iron beasts", only the warriors of the highest standing in a clan were given the honor of piloting a Basilisk droid
This isn't to say that there aren't that many, but its not as many as you would think.
Thank you. I feel much more capable of making a fair guess as to how this battle will end up now.