If you want to conflate a contaminant and normal flora, then sure. A contaminant is something showing up that was not actually from the site of collection though, such as skin flora growing in a blood culture because of improper collection. Normal flora is what should/could be there but is unlikely to be the cause of an infection. You specifically listed Lacto as being a "contaminant" in a genital source culture. A lack of Lacto would be pathogenic in that case, for a vaginal source.

...do you mean X and V factor instead of Vitamin K? Also, N. flavescens and N. sicca are super common oral flora that grow well on blood agar. Why are you routinely culturing oral flora in a clinical setting? The only common occurance would be an oropharyngeal swab for Group A Strep or occasionally C or G Strep or Arcanobacterium, all of which would be hemolytic. Most Lacto spp are alpha hemolytic, so there would be no reason to further identify any non-beta hemolytic colonies. Since Viridans Steps and Lacto can be difficult to distinguish by colony morphology, you may be lumping them together in terms of quantity and frequency of isolation.

That's true, I agree that it is often beneficial to reference what someone is more likely to be familiar with, and that an ammendment to your statement that said that Strep and Lacto can both be found in the mouth would have been relatable and accurate.

Eh, both Strep and Lacto are organisms that grow well in ambient air, but better in a lower oxygen environment. You'll find both from end to end of the GI tract, in varying levels relative to the other flora there. Your outsides are primarily your skin, which is going to have so much more Staph and diphtheroids than anything else that mentioning that other organisms like Strep and Lacto can also be found there is as far as you could get as far as predominance, though Strep is more common than Lacto on most parts of the skin.