Hi,
Following my own eperience, i do not modify anything if the network is not subject to strange behaviours.
Maybe i short time testing with defaut setting could be interesting for you. But if you are aware of identified problems in relation with these settings, then you can try to modify them from scratch.
mac-age-time <60-999960> - default 300
ip arp-age <1-1440>/infinite - default to be check in the documentation ... sorry
Bye,