This is the website of bishop Missael, the Coptic bishop who has responsibility for ethnically Egyptian churches in the Midlands. So he is a brother bishop of our own Abba Seraphim, and they are both bishops of the Holy Synod of the Coptic Orthodox Patriarchate.
Certainly Abba Seraphim is senior because he is a Metropolitan bishop but he has not authority over the Coptic Churches of Bishop Missael because the British and Coptic communities exist in parallel in the UK. So there are three Coptic bishops responsible for the Coptic communities, and one British bishop responsible for the growing number of British communities, all within the same Coptic Orthodox Patriarchate.
The Stevenage Church is under Bishop Angaelos, another Coptic bishop. In fact there is an Oriental Orthodox festival there at the Church centre this Saturday and many British Orthodox folk will be attending, as will clergy and lay people from all the Oriental Orthodox communities in the UK, so Armenian, Coptic, Eritrean, Ethiopian, Indian and Syrian as well as visitors and friends.
I hope this explains a bit.