Just as an example, the biggest Ensembl Families are aligned with mafft auto and they are big:
+----------+-----------+ | count(*) | family_id | +----------+-----------+ | 54909 | 1 | | 19735 | 2 | | 14461 | 4 | | 12625 | 5 | | 10452 | 3 | | 9223 | 6 | | 9178 | 57 | | 7842 | 9 | | 7568 | 7 | | 6810 | 8 | +----------+-----------+