I have both and the Crawler and Holydiver do have a connection as both are smooth and have plenty mids but where the Holydiver is thick, the Crawler is fat.
I also have both and tried them in the same guitar (a PRS Custom) and I fully agree to that statement. I did not try the Abraxas bridge in that one, though.
I'd say the Crawler is closer to the Holydiver than the Abraxas. Perhaps the Abraxas is another step further down.
I have played the Holydiver and Abraxas bridge also in the same guitar (but not the Crawler bridge in that one) and I have to disagree. To me the Abraxas sounded closer to the Holydiver than the Crawler did compared to the Holydiver in the PRS.
In another guitar I had both the Crawler and the Abraxas bridge (but not the Holydiver). The Abraxas sounded noticeably brighter than the Crawler. I would rank them as follows (most to least):
Brightness: Abraxas - Holydiver - Crawler (I hear higher highs in the Crawler but more high midrange and less low midrange in the Holydiver which makes it appear to be a bit brighter)
Midrange fatness: Crawler - Holydiver - Abraxas (the Abraxas being not far behind the Holydiver)
Bass: Crawler - Holydiver - Abraxas
Output: Holydiver - Crawler - Abraxas (the Crawler being almost on par with the Holydiver)
To OP: Tim's recommendations are usually good but if you are leaning more towards the vintage side of things the Abraxas bridge should work well. I have not played an Emerald neck (that is definitely on my to try list) but if it works well with the Holydiver I imagine it would work equally well with the Abraxas - same wire gauge and same magnet type.
Hope that is helpful,
Stephan