There is more than one Saint Iosaphat. There are seven Iosapaphat mentioned in the bible, so there are seven St Ioaspaphat recognised and celebrated by the Greek Orthodox tradition (alone). So the saint in question (the Rusian saint) may not necessarily be named after the specific St. Iosaphat Son of the Indian King Avenir. This is why there is a epithet attached to the name, to distinguish which Iosaphat is pictured in the icon and is being celebrated.
For example I am named Gregory, right? I am named after Saint Gregory the Theologian of Cappadocia (Nazianzou, to be exact), he is celebrated on the 25th of January according to the Greek Orthodox tradition. But there are another 40 Saint Gregory recognised by the Orthodox tradition and celebrated on different days.
With the eye of wisdom we discover a lot of anger in us, any amount of jealousy, resentment, ignorance, desire - mountains of emotion whose existence we would never have suspected in ourselves... We recognize that most of the faults we perceive in others are only the mirror of our own negativity, the reflection of our own disturbed feelings... At the same time, we relieve the world around us of the burden of our own negative judgements."
Gendun Rinpoche Heart Advice from a Mahamudra Master