If this is a recurring pattern, in which you need to add those ~60 weekly IPs to the same few groups, it might be worthwhile to evaluate the use-case and consider alternatives.
For example, if those 60 IPs are malicious / bad reputation IPs that you want to block, then instead of automating them into a group and pushing policy, consider using IoC feeds for blocking in Threat Prevention blades, or a Network Feed that can be placed into a FW policy block rule.
If those IPs are going into a few certain groups that are effectively owned by another team for opening traffic to certain resources, you can also consider a Network Feed with an allow rule, and either fill in the feed yourself or allow that other team to control it.
Using the above alternatives will save you the need to push policy to all your gateways after every update, and will "de-clutter" your Management as you won't need all those host objects.