They will at least have the bitshares port open. And most likely SSH as well.
There are way (, way) more than 101 bitcoin miners. I would guess the specs for a bitcoin miner will tend to be much more buffed too.
Why BitShares port open? They operate as network clients and connect to other nodes only. SSH port, yes, if it's VPS but SSH ports has custom number and usually protected from DDoS by VPS provider.
How you will get delegates IP, if blocks propagated by network and your client usually get it from other clients and not directly from delegate?
Delegates are clients too, I really haven't thouroughly checked what the client is doing at the network level, but:
BitShares 986 $user 54u IPv4 34849 0t0 TCP xxx:48096->216.146.143.195:1776 (ESTABLISHED)
BitShares 986 $user 66u IPv4 45237 0t0 TCP xxx:54789->185.82.200.187:1776 (ESTABLISHED)
BitShares 986 $user 82u IPv4 76344 0t0 TCP xxx:54849->104.131.185.84:1776 (ESTABLISHED)
BitShares 986 $user 139u IPv4 78859 0t0 TCP xxx:40946->cpc3-cmbg14-2-0-cust343.5-4.cable.virginm.net:1776 (ESTABLISHED)
BitShares 986 $user 143u IPv4 33992 0t0 TCP xxx:60337->185.82.200.106:40027 (ESTABLISHED)
BitShares 986 $user 144u IPv4 31742 0t0 TCP xxx:37187->216.146.143.206:1776 (ESTABLISHED)
BitShares 986 $user 145u IPv4 31743 0t0 TCP xxx:51099->
www2.minebitshares.com:1776 (ESTABLISHED)
BitShares 986 $user 146u IPv4 33643 0t0 TCP xxx:47911->vmi34425.contabo.host:35453 (ESTABLISHED)
BitShares 986 $user 147u IPv4 34011 0t0 TCP xxx:53679->42.96.186.61:1776 (ESTABLISHED)
BitShares 986 $user 148u IPv4 34014 0t0 TCP xxx:41496->
delegate.dposhub.org:1776 (ESTABLISHED)
BitShares 986 $user 149u IPv4 35335 0t0 TCP xxx:37978->
bitsharesnode:1776 (ESTABLISHED)
BitShares 986 $user 150u IPv4 34029 0t0 TCP xxx:54079->
colo.hostirian.com:42990 (ESTABLISHED)
BitShares 986 $user 151u IPv4 75755 0t0 TCP xxx:38961->67.4.107.92.dynamic.wline.res.cust.swisscom.ch:1776 (ESTABLISHED)
BitShares 986 $user 152u IPv4 34031 0t0 TCP xxx:53362->
li699-30.members.linode.com:1776 (ESTABLISHED)
BitShares 986 $user 153u IPv4 34032 0t0 TCP xxx:45142->178.62.30.153:1776 (ESTABLISHED)
BitShares 986 $user 154u IPv4 34033 0t0 TCP xxx:56829->104.131.134.181:1776 (ESTABLISHED)
BitShares 986 $user 157u IPv4 34034 0t0 TCP xxx:57893->198.199.106.13:1776 (ESTABLISHED)
BitShares 986 $user 158u IPv4 34933 0t0 TCP xxx:52255->95.215.47.201:42315 (ESTABLISHED)
BitShares 986 $user 160u IPv4 36981 0t0 TCP xxx:60288->
li424-154.members.linode.com:1776 (ESTABLISHED)
BitShares 986 $user 161u IPv4 35399 0t0 TCP xxx:58871->
li430-37.members.linode.com:1877 (ESTABLISHED)
I'm willing to bet the bold ones are delegates. If so, this means clients also connect to them.
If so, then it is trivial to isolate them. They will be the nodes that are constantly running. Simple network analysis spread over a few days will give you the full list.