I suspect there is some misunderstanding going on here, although that will depend on what you mean by "macro". You have three very capable macro lenses that all achieve 1:1 magnification. If you actually use those lenses at 1:1 magnification, a smaller sensor gives you two things: a smaller FoV and shallower DoF. The only thing you gain with the smaller sensor in that situation, assuming the smaller sensor has a sufficient FoV for your subject, is likely more pixels on your target (assuming the smaller sensor has a higher pixel density).
OTOH, if you match framing, such that you're further away from the subject with the smaller sensor (lower magnification), then you do get deeper DoF with the smaller sensor. You may or may not get more pixels on target (if you're filling the frame at equivalent framing, the sensor MP count will determine pixels on target). In that situation, you can usually achieve the same DoF by stopping down the lens more with the larger sensor, and generally your IQ will be better with the larger sensor and the stopped down lens (but if you are at the minimum aperture for the lens, you'll buy a little more DoF with the smaller sensor...at the cost of more diffraction and thus lower sharpness). The only significant advantage of the smaller sensor in that scenario is the increased working distance, which is certainly useful if you are shooting live, skittish subjects.
In other words, for 1:1 macro work there's little to no benefit with a smaller sensor (more likely a disadvantage), and for close-up work it's pretty much a wash unless you really need more working distance (which may be the case given that you purchased a 150mm macro lens).
Some food for thought...