The subject of names can be considered either deeply confusing or fascinating, probably a fair bit of both. What are widely regarded as the names of deities recorded in inscriptions may, in fact, be descriptive epithets. Cernunnos may fall into this category since it simply means ‘the horned, or antlered one.’ Many other recorded deity names are similarly descriptive, e.g. Lugos, ‘light.’ As was mentioned earlier, Cernunnos only appears on a single inscription and has simply been assumed to be the name of other horned or antlered gods who appear elsewhere. It is possible that all of them were called Cernunnos, but equally possible that each had a different name by which they were known to a particular tribe or in a specific area.
The presence of the antlered figure from the Gundestrup cauldron in a posting about Gwydion ap Don is probably my fault 😉 I first ran across that image decades ago and it immediately spoke to me, giving me my image of an archetypal Druid, one closer to a shaman than the biblical patriarchs of the 18th century Druid revival. Having first read the Mabinogi stories more than forty years ago, I have read them many times since and worked with them in many ways, from story-telling to group ceremonies. During that time, the figure of Gwydion has grown into my consciousness, in part as a result of an encounter with Woden I had on a burial mound south of Avebury. In recent years, what radiated to me from the Gundestrup antlered figure and my growing awareness of Gwydion as a living entity have merged to some extent. So yes, I see them as expressing a similar force in the world, and a powerful one at that, so much so that I have the Gundestrup image attached to the wall above my computer screen. Thinking about it, the link has been with me for longer than I thought. The Druid Tarot deck I began work on in the 1980s has Gwydion represented by my lino-cut of the antlered figure from the cauldron. You can see it here: https://greywolf.druidry.co.uk/wp-content/uploads/2014/10/23Gwydion.jpg