There is another early Christian site near Loch Awe you should see.

The sites from Ormaig and Loch Craignish extend far to the North. I would suggest they extend well beyond the Barbreck River Valley, beyond Seil, Easdale and Kilmelford and the wee valley of Loch Nell (East of Oban) and Strontoiller, on past the massive cairns beyond the tidal Falls of Lora and as far as the many cairns at Benderloch and Creran. Even Lismore is infested. There are forts, duns, settlements, cists, cairns, chambered cairns and some RA.
South from Loch Craignish is of course Kintraw (with its massive cock "waymarker") and then the Kilmartin Valley, the Kintyre Peninsula and Isle of Arran. All hoaching with antiquities from the Neolithic to the IA. Some Mesolithic too. They all form a long arm North of The Irish Sea and have some individual peculiarities which have been noted in some of their cairn constructions etc.

They are all on an abundantly plentiful seaboard of what is now called Western Scotland. The broad flat Kilmartin Valley with Carnbaan and Dunadd at its Southern end are the widest and easiest worked agricultural land, the river valleys and coastal strips I mentioned above are next best. The whole area is still plentiful in Sea Fish and shellfish. Salmon and Sea Trout runs are still quite good (though hardly 1% of what they would have been in the BA and early Iron Age). It was Fat Land and they lived very well off it.

The evidence is these early people lived and died on abundantly nourishing coastal and fertile river valley areas. The evidence is that early people made the sea journeys specifically to take advantage of the plentiful food available. Sometimes returning for seasonal migratory fish. They also took great care in burying their dead. Some of the later occupants of these areas we know about, were seafarers (from what is now Norn Irn but even Irn didn't exist then) who lived on the land and islands and their Christian stowaways who built and worshipped in their wee chapels and churches. I've never seen or heard of any evidence of pre-Christian religious worship in Kilmartin. I've seen plenty evidence of Life... creative and groovy RA, shell middens, stone tools, later Bronze implements, Neolithic Cairns, BA Cairns... but not any evidence of religious worship.