A fresh installation of a openSUSE leap (15.3) as a server resulted in chrony
tracking 18 time sources

localhost:~ # chronyc sources | head -n 1
210 Number of sources = 18

These are coming from two places - The first (expected) is via the
chrony-pool-openSUSE

localhost:~ # cat /etc/chrony.d/pool.conf
pool 2.opensuse.pool.ntp.org iburst
localhost:~ # rpm -qf /etc/chrony.d/pool.conf
chrony-pool-openSUSE-3.2-9.24.2.noarch
localhost:~ #

however it looks like something at install time alters the standard chrony.conf
localhost:~ # rpm -V chrony
S.5....T.  c /etc/chrony.conf


and adds multiple "pool" entries in a manner which looks like something that
originally used "server" entries

localhost:~ # grep ^pool /etc/chrony.conf
pool 0.suse.pool.ntp.org iburst
pool 1.suse.pool.ntp.org iburst
pool 2.suse.pool.ntp.org iburst
pool 3.suse.pool.ntp.org iburst
localhost:~ #

I think this could be related to #1180689 and #1172517 - but I can't work out
what takes the server list generated by
https://github.com/yast/yast-network/blob/master/src/lib/y2network/ntp_server.rb
and adds them to the config.


IMHO, the solution is not to add any pool entries into chrony.conf if already
using the include /etc/chrony.d/*.conf method. 
If they _do_ need to be added, one pool entry should be enough.