Most gods from the same general region, or even the same continent, can be linked together. As an example, Aphrodite is obviously linked to Venus, but is also linked to Hathor and Freya. You can view different gods as different aspects of the spheres that they control. I wouldn't abandon any gods just yet, but I'd work with specific pantheons one at a time and see which one you feel connected to most. I personally work with the Roman and Greek pantheons, and I interchange them as I see fit.
As an example, if I want to work magick for wisdom and clarity I'd invoke Athena, however, if I wanted to work magick for wisdom and clarity but wanted to have a little more aggressiveness with it I'd invoke Minerva.
It's mostly about what you are most comfortable with, and the beauty of magick and witchcraft and paganism or Wicca or whatever path you walk is that it's YOUR path and you decide how you want to walk it, you know? Some people don't even include gods in magick! It's all very personal.
Well...all "gods" are real. I'll explain because its not always what it is believed to be. "Gods" refers to beings with natural born abilities. Essentially they physically existed at the beginning of civilizations across the world. Eventually they died out, however spirits never cease. And it is possible to evoke and pray to deities in whatever culture you choose. Yet calling upon a deity isn't just something most people can do because they don't answer to everyone. More than likely you'll call a lesser being but because any spiritual being presence and power is greater than ours, you may mistake it for one of those deities.
Liibra, most Gods can be linked in a vague way, that doesn't make Them the same Deity even remotely. Some Gods are even historically linked in that Their devotees traveled and compared or compounded the two; this still doesn't make Them the same.
Roman and Hellenic Deities are a special case in that Their names do interchange better than most, but even They aren't technically the same as each other. Each culture has their own worship of their own Deities or Deity, they should not be compounded and called all the same but rather treated on a individual and independent various if they are from different places.
In my opinion, I appeal to reason. Physical reality around me demonstrates two obvious features. One is that it moves through time the other is that it bears the marks of design. It seems that the evidence shows that the Universe or Multiverse has a beginning. So then it needs a beginner. Time is a part of the Universe it self. So the beginner is not subject to time. So reason tells us that the Beginner is Eternal and the Source of all being. Things seem to be designed so that tells us the the beginner is intelligent. These are all clues that tell us something about the God who is actually there. This is my opinion.
I mean if your half Irish and half Native American then Celtic and gods of your tribe are the gods of your ancestors but that doesn't mean that other gods are fake think of it like the gods that rule over your bloodline and traditions but now due to the glory of the internet you can take from other traditions
I don't know if this helps but I hope it does. In my believes as a native American we Don't have specific names for godly beings they are known as The creator, father sky, mother nature, brothers and sisters etc. so when I hear or read about other cultures and their gods that are similar I just say to myself that's what they know father sky as because I believe they were not bound to one race or territory or landmass but work throughout the planet and it was the story telling, culture, and people's limited ability to understand that made them differ.
