Checking Company with Companies House

I'm getting quotes for some building/decorating work which will cost around £7k which is a lot of money for me so I want a trustworthy Company. One of the company's when I looked on Companies House had a director called Peter Anthony Valaitis who was appointed and resigned on the same day. On further searches this name appears as a director of over 15,000 companies mostly appointed and resigning straight away!! What is this all about and is it legal/dodgy??