I'm not the biggest believer in this, although it does make passive speaker design MUCH easier. if I recall correctly, Dennis Murphy used around 14db of attenuation on the RAAL tweeter on the soundscape to match the sensitivity of the woofer. As a general rule though, As you go up in frequency, your sensitivity should go up. You don't want to passively attenuate at bass frequencies as much as at tweeter frequencies. And I generally remove 3db or so from a speaker's sensitivity rating to account for baffle step compensation.Efficiency of the woofer compared to the other components.
What is power compression, though - thermal limitations - I wonder how valid they in real world, home usage. Are we talking about electric guitars for 3 hours, or a hard drum hit every few seconds?Even if you go to the active route, I wouldn't personnally like to match a 97db/W/meter woofer to a 85db/W/meter mid and a 88db/W/meter tweeter. Those component do not have to go into power compression. It could work ok for balancing the sound at low to medium level but the lowest efficient component could easisy go into power compression so dynamics would shift in some frequencies compared to the others.