SBMM has to factor connection quality and current available player pool. SBMM makes a bigger impact in the Free Lance queue since the game can mix and match players until both sides have a similar Glory average. In the regular queue, matching options are much more constrained, so if you are the best qualified group to go against a full Unbroken team at matchmaking time despite your rank being < Fabled, then you will get the dreaded stacked pairing. Connections are still factored, so there are two similarly skilled groups matching on opposite ends of the Earth, then the game will not connect them if latency exceeds a preset threshold.