lancelot
Completely worth it
We know OOC that Palps planned to destroy Dooku, and Dooku hoped to take out Palps and Palps intended to establish absolute personal control, but Jango I guess hasn't quite realized that.
You think you are underestimating how useful hindsight is. We know what the Sith are planning, but Jango only knows that they are Sith, they are secretly controlling both sides and that they are building a secret clone army to be led by the Jedi and turn turned on the Jedi via mind-control chips. He can guess that the Sith want galactic domination as usual, but he has no idea what form that will take.
Even in universe Sith Backstabbing Syndrome is a known and constant failing. I still think your overcompensating for OOC knowledge, if Jango wasn't a Mando with with a education in their military history that includes fighting with and against Jedi and Sith he might not catch on. But a Mando in his position is the perfect person to know what the Sith are going for. Maybe not the details but enough that the details don't matter.