I think I've got the Eusebii sorted out ... but it'll be no skin off my nose if somebody better informed can correct me.
Today we commemorate S Eusebius.
S Eusebius, that is to say, of Vercelli. He was a resolute anti-Arian who galumphed around promoting orthodoxy, refuting heresy, back in the dark days when (in S John Henry Newman's neat analysis) the Teaching Authority of the Church was In Suspense, because so few bishops were prepared to stand up against the Arian Heresy. That heresy was so terribly popular ... backed by intellectuals ... supported in very high places, even the then equivalent of the White House ... 100% side by side with the Zeitgeist ....
You might call S Eusebius of Vercelli a sort of proto-Schneider.
But this Eusebius is not to be confused with another Eusebius, S Eusebius of Samosata. The possibility of confusion is made even stronger by the fact that this Eusebius was also a doughty warrior in the struggle against Arianity.
In fact, he went even further than the Vercelli Eusebius. In his extensive travels encouraging orthodoxy, he actually consecrated bishops for churches which either lacked a bishop or whose bishop was an Arian. This was uncanonical, even before later canonists invented the importance of the Mandatum Apostolicum; and the latae sententiae threats nowadays aimed at Bishops who take it upon themselves to consecrate other bishops without that all-important letter from Rome.
You might call S Eusebius of Samosata a sort of proto-Lefebvre.
That must be why he is not in the current edition of the Roman Martyrology ... Oops; he is there, splendidly sharing June 22 with Ss John and Thomas of England. Silly me. I should have checked before ranting ...
A big temptation to which bishops, poor poppets, can fall victim is the temptation to see themselves as a managerial elite, and to deem their main priority to be fostering harmony with members of other managerial elites. Not least, elites outside the Catholic Church. There was feeling both in the 1990s and in the 2000s that the English Catholic bishops considered snuggling up to Anglican bishops to be more important than welcoming Anglican fellow-Catholics into corporate unity. Cardinal Ratzinger mused "What are the English [Catholic] bishops so afraid of?
But that Ratzinger never made a fetich of the 'ecumenical' idea of all-of-us-manager-chappies-sticking-together.
Back in 2003, when dissident American Anglicans were meeting and plotting in Dallas in the lone-star-state, they were extremely surprised to get a telegram from Cardinal Ratzinger warmly offering them support and friendship.
The "Panzer Cardinal", indeed. "The CDF used to be called the Inquisition", the Media helpfully, pompously, and incessantly reminded us.
The old Bavarian gentleman was ... is ... a very great Churchman and Christian. As were the Eusebii, both of them ... as well as certain more modern ecclesiastics I could list.
Orent pro nobis.
Vide The Church and its Divine Constitution by Dom Adrien Grea, Chapter 21.