Theoretically, can a solar system evolve around lagrange points My question is, during the evolution of a solar system is it possible to end up with a massive planet around a star with two small planets around their $L_4$ and $L_5$.
Since we know it is not possible to have any bodies around $L_1, L_2, L_3$ due to their low stability, hence any planet trying to evolve their can be easily nudges out of its position.
Yes, provided the star is big enough, the "Jupiter" is big enough and the planet is small enough.

The details are discussed herein: "Is there a ceiling for stable L4 or L5 masses?"

To summarise: The sun needs to be 25 times more massive than the giant planet, and the small planet needs to have negligible mass.

It is worth noting that the minor body could not be said to be dominating its orbit, and so would be considered a dwarf planet by the IAU.