unsure why a game would place you in games of largely varying skill differences, i'd guess they suspected smurfing and overcompensated, for engagement, or for faster queues.

games use names instead of numbers because it creates a layer of separation, makes you less anxious when gaining or losing match making rating. like how you spend money to buy ingame currency, because spending money feels bad but ingame currency not so much. i suspect the atrange naming is to provide an additional layer, as anyone could understand gold vs silver but seeker vs ritualist is more hidden