mgmt$ALERT_CURRENT volume
So I'm checking table/view mgmt$ALERT_CURRENT to check all my current Alerts in the full OEM instance, for ANY object no matter what type, and the result was very surprising.
As Critical alerts can only exist, if they once potentially were at the level of Warning, the logical thing to expect is to find more Warning Alerts, and thus less Critical Alerts.
The amount should always be as low as possible, preferably, but with this relation : more Warning than Critical.
That is, for a SANE environment. If everything is wrong, in that case maybe there's more Critical, but lets assume we have sane environments.