Pictured below are optimal synergies that can be made with collection characters. As useful as this resource is, however, it also exposes an issue with the current synergy system - synergy isn't balanced for every class.
4th and 3rd paths are the only ones who can get Magical Specialist, there are no physical amps at all for DPS synergies, Third Path has no Fist Fight, 2nd path has to sacrifice Fist Fight for Nasod Research, etc. If you were a 1st or a magical 4th path, you won at character select in terms of getting the best synergy.
On top of unequal distribution of synergy, we simply just don't have enough space to be more flexible with synergy. A class like Minerva would definitely benefit from Angel of the Battlefield, but because we only have 6 slots, she can't utilize it.
The final issue with synergy is the allocation of certain effects. Why are 4th paths the only ones with access to Distorted Gaze?
My suggestion is to reallocate synergy effects so all paths are able to be granted the same bonuses. Furthermore, changing synergy or outright removing some useless synergies such as Attribute Master and Blessing of Mana to either have better effects, or replacing those effects with good, existing ones. Additionally, add more synergy slots so more of them can be utilized, or lower the amount of characters needed for important synergies such as Sharp and the Path specific synergies.