What ratio of power in tri-amp system ?

In order to better utilize equipment , is there a formula or chart somewhere that recommends what wattage power amp should be used for each power amp in a three way system ? I realize that crossover points and speaker component's individual performance spec's would cause great variation , but is there some kind of rule of thumb for a starting point ? Is this too vague a question ? I have a PA system with separate cabinets for all speakers and would like to know whether I have enough power for the speakers or need to get more speakers for the power .
I have an active bi-amp system.

Quality is actually more important than quantity.

I personally use Krell amps, all of which have the same gain. Since mine are different models, I use the best one for the mid/highs and the older one for the bass. If I had three different ones, I would use the best one for the mids.

I did see a set-up with the B&W Nautalis, which is a 4 way speaker. They had all new amps. They used the biggest for the bass and progressively smaller for each speaker up to the tweeter.

I hope this helps.
Power in and of itself has nothing to do with the quality or dynamic nature of the sound. You need to match amps with speakers. This works in many ways. I have 125 wpc amps running revel studio with tremendous dynamic sound. I also used 350 wpc amps and had great sound as well. No better dynamic sound. There is no formula.
Sounds like you already have amps and speakers. I suggest that you play some music, various selections, the way that you intend, and measure the voltages being applied to the high, mid, and LF drivers. This will tell you which speaker is using the most power, and the least. If there isn't much difference, select for audio quality per previous comments.
If one is a hog, give it the watts.

This article gives some formulas, along with others on the site. Input gains being matched along with proper power output matching are the key criteria along with each drivers sensitivity in order to get a flat frequency response across the band. The other articles might help.