As previously announced (source), several matchmaker mechanics are being updated:
Almost all battles will now be single-tier or follow the “±1 tier” rule. Only about 5% of battles will be “±2 tier.”
New limitations for Random Battles team composition:
• No more than 2 SPGs
• No more than 5 TDs, with a maximum of 4 sniper/support TDs
• No more than 2 LTs (for Tier VII–XI battles)
• Grand Battles: no more than 4 SPGs, 4 LTs, and 10 TDs (with up to 7 sniper/support TDs)
Important! The number of “preferential” battles for players using a newly acquired vehicle will be increased.
Previously: the first battles were guaranteed to be either single-tier or top in a two-tier battle. This stopped working if the player/platoon waited more than 60 seconds.
• Tiers I–III — 1 battle
• Tiers IV–VI — 2 battles
• Tiers VII–X — 3 battles
Now: the first battles will place you either in a single-tier battle, top in a two-tier battle, or top in a three-tier battle. The rule still stops applying if the player/platoon waits more than 60 seconds.
• Tiers I–III — 2 battles
• Tiers IV–VI — 3 battles
• Tiers VII–X — 5 battles
Achievement Changes:
Due to team composition adjustments, the following medals will no longer be obtainable:
• Naidin’s Medal – Destroy all enemy light tanks in one battle (at least 3).
• Burda’s Medal – Destroy 3 enemy SPGs at least one tier higher than your vehicle in one battle.
• Dumitru’s Medal – Destroy 3 enemy SPGs in one battle.
Don’t panic! Previously earned medals will remain displayed in your Achievements section.
More details coming soon — stay tuned to our official channel: Mir Tankov.

Just an idea, how about same amount of idiots on both sides ?
And those with gift tier 10 tanks are considered useless by default…