Our route table has:
*> 198.111.252.0 192.41.177.145 <--- agis
*> 198.111.252.0/22 192.41.177.181 <--- mci
*> 198.111.253.0 192.41.177.145 <--- agis
*> 198.111.255.0 192.41.177.145 <--- agis
This isn't what agis is supposed to be announcing, I'll have to
ask them again to announce 198.111.252/22. There's a couple less
routes already :-).
Once that is fixed, further aggregation of 198.111.252.0 (say into
198.111/16, as a non real example) would change our routing (in
ways we don't want it changed), even with your "next hop the same"
criteria because of the additional meaning that specifics have in
terms of priority.
I agree that your tool is usefull in identifying _potential_ savings.