Sorting by scaled helps a little bit, but some communities just post soooo much that they drown out everything else. In order to fix that you would need “multireddits”, which don’t exist on Lemmy.
For the time being, I recommend making two accounts and using one exclusively for subscribing to the really busy communities. The other one could be used for everything else. It’s also an opportunity to try out a different instance.
If you find that one feed is getting dominated by a single community again, you may need to create a third account to manage your subscriptions appropriately.