If easyjet were to open a base at BHX, it is likely to be 3 based aircraft at most.
3 seems to be the benchmark for trying/testing operations to see what works. SEN opened with 3, NCL remains at 3, EMA was closed at 3 and other airports have opened with 3, but cannot remember which ones.
To open with 10, and more so 10 this year is just spotters fantasy.