Every accredited registrar for a specific TLD is assigned a set of credentials (login details for want of a better term) for connecting to the registry for domain reg/update/renew/etc
Those connections are limited (in number of concurrent activities) and in performance (speed/capacity) as well as being affected by thinge like HW capabilities, local and upstream network, route-between-ASNs and many more factors.
This is why _some_ dropcatchers operate _hundreds_ of inter-related registrars (ICANN love this as it's millions more in quarterly fees to fritter) and the most advanced then disperse the actual machinery that is doing the catch to locations where there are short "links" between catcher-system and registry-system.
In general less switching, less cabling, less 3rd party networks etc all contribute *in a very very small way* to the ability to "be first" in a race (assuming everything else about the software/systems are mostly equal)
That's very high-level without delving into the drop date/time, status monitoring, difference between info/avail epp checks and reg attempts etc
In "pecking order" at best it could be balanced into a "tree of opportunity"
Registry at the top
Each individual Registrar equally underneath
Each Reseller equally underneath
Handreggers equally underneath
Opportunists under that
Bear in mind that more than 50% of the 400million domain names do nothing but cycle around domainers/drop-catchers/speculators - and often the %age is much higher as domain-age plays a part
e.g. of 1735 domains in pending-delete at one registrar when I did some checking 726 of them had dropped previously and only 187 of the others had been anything other than "parked" prior to expiry - whilst not a large sample, the inference is sub 15% of names get really "used" for something and around 50% of domains that are just bought to resell, do not sell, and get eventually dumped only to repeat with the next domainer/catcher !