Discovery compares drivers by score divided by the most a driver could score, and that maximum summed every positive rule. Rules that never match together, such as one vendor's landing page or another's, made a driver that knows several vendors lose to one that knows none: napalm-redfish's Supermicro landing page scored 6 of 41 and lost to a bare "linux" in the same BMC's SNMP sysDescr, 5 of 18. FingerprintRule gets an optional group. rules_max_weight() sums the positive rules and counts each group once, with its strongest rule. Existing rules have no group and count as before.