It's the case since a longer period allready. The opponents at the top of your list, who have less arena points than you, can come from the previous tier, the opponents at the bottom of the list from, who have more points than you, come from the next tier.

Yes, this would make sense IF opponents came from ONE tier above/below not  TWO tiers above. 

Never saw team from S1 :)

Hmmmm Never noticed that 

BUT I have Noticed opponents recently with 1500 points down into Tier I 

I also get Defense Teams that have Bad El and Arbiter on them that ONLY have 900 or so points and are in Tier I , 

HOW Does someone with an Arbiter and Bad EL sit with 900 points in Bronze I ....

Definitely  F U B A R   

arena is a joke.  matchmaking is completely based on player power.  i bought a TON of shards at the beginning, trying to get some really good champs.  kept a copy of each champ.  now i have 1.2M player power and can't get out of bronze 1.  every single team is full of legendary niche arena champs.  so i guess i'll never get an arbiter... or complete any missions past get to silver.  well played plarium.  penalize me for spending money on your game.  makes sense