Today, the developers of Fire Emblem Heroes sent a notification about upcoming adjustments impacting Arena matchmaking, that will go live with the next Season on February 27th.
Here’s how it works now: when you select a difficulty level (Beginner, Intermediate, or Advanced), the strength of your opponent is then selected from a set range of strength based on the difficulty level you chose. That selection is done based on your team’s strength when you select Battle.
With the adjustments to be implemented on February 27th, it’s possible you will end up with a slightly weaker opponent (with a lower score than in past Seasons). It’s actually an intended side-effect of the new system, which aims at preventing you from getting matched up with a significantly weaker opponent.
Naturally, the reasons the developers went and made those adjustments is to make sure players can enjoy the Arena by being matched up to the right opponents. It’s especially true for players with really strong teams: with this new system, they’re less likely to be matched up with teams with extremely low scores… not really the kind of opponents you want to end up with when you’re looking for a challenge.
The developers will provide more details in another notification, on February 27th.
Source: Fire Emblem Heroes