These names are part of culture & civilization which predates hinduism/vedic religion & got linked to gods over time. Vedas could have been in any language but they were in sanskrit because Rishis got wisdom in their own language which they used to speak and words similar to these also appear in other languages. All these names have a meaning such as 'Ram/Raam' means omnipresent, 'Narayan' means a place where human finds a shelter or onw who resides in every human,etc. This is well known but people strictly try to link them to Hindu gods for ego boost. Hindu gods, avatars, idols are not considered supreme God in Sikhi. Names are used for both God/Vaheguru & hindu gods so context is important. An example: Page 1429- ਰਾਮੁ ਗਇਓ ਰਾਵਨੁ ਗਇਓ ਜਾ ਕਉ ਬਹੁ ਪਰਵਾਰੁ॥ raam gayo raavan gayo jaa kao baho parvaar. Raam Chand passed away, as did Raawan, even though he had lots of relatives. Page 1429- ਰਾਮ ਨਾਮੁ ਉਰ ਮੈ ਗਹਿਓ ਜਾ ਕੈ ਸਮ ਨਹੀ ਕੋਇ ॥ raam naam our mai gehiou jaa Kai sam nehee koe. I have enshrined the Lord's Name within my heart; there is nothing equal to it.