Hello @hdeejayyy ,
Thank you for reaching out to us.
Are you find this to be the case in Ranked or Unranked?
As when it comes to matchmaking, the system will attempt to balance teams out to an equal average MMR.
This can sometimes involve one higher level player being matched into a team of an overall lower rank to balance with a team of more equally ranked players. And this is also applied during off-peak times to help reduce queue times.
Regarding smurfing, this is something the team are also in the process of taking actions to address on a larger scale. You can read more on their plans in their Reddit AMA available here.
If there's anything more we can answer, please let us know!