Is it a problem if my individual bank accounts do not show 500,000 baht for visa purposes?

Ok must move all into one straight checking account. But after that just depends on the embassy .... As long as I show the money in the accounts ... Then show it all moved into one you should be ok.

This for business or soft power?

My experience in Laos ..Vientiane ....was I had my Australian bank account that I use all the time when there ...as have an a/c here ..but didn't mention that ...so I transferred enough money to be over 500,000..I converted it to baht in my Australia bank ...with yellow high higher ...all she asked was ..your mobile account ..where's that ...I asked what's you mean .... mobile ...she ask for everyday transactions...I told her that I not use my card ..just transfer into my partners account..she is Thai ..and I put out 40,000b when I need money ...pick up my visa 2 days later ..did that transfer ...528,000 b was 3 days before I went to put my forms in ...I also had lots of activity in that account ..for buying stuff online , money transfers stating .."Thai Money" ...not over counter ..very rarely purchase products over the counter with my card ..

It depends on what embassy you are applying at. I only showed 1 month with the ending balance of the required amount at Washington DC embassy.