Welcome Haydarpasa -
This topic would probably be best served in our Acoustic Music forum as that's where all the live, orchestral recording guys/gals hang out.
In any case, yes, you should be able to use different brands with no problem. Granted, your best sound will come from three matched mics; however your setup should work.
When doing this, I've typically used my "darker" mics on the outer edges and the brighter mic for the center mic.
As for reaching down to 3Hz, I haven't heard too many that would go down there (haven't tried the Earthworks) but the Gefell M296s I use go down to DC and I do notice a few things with it that I don't with my Schoeps. If you do a gentle HPF below 30Hz, you'll gain back an additional 5dB of noise floor.