I am of the opinion that Richardson will likely be the starter at the 3 for the beginning of the season, but that could change depending on how good Hubbs actually is. Truth is that we don't know how good he is, we will just have to wait and see, but I tend to err on the side of caution and think he will just be good, not great.
I do think that Josh will log a lot of minutes at the 4 this year in relief of Stokes and Maymon and that could factor into what the starting lineup looks like. Maymon may not be able to put up a ton of minutes depending on health and conditioning in relation to his injury. Stokes is not a guy you want to see play 40 minutes, he needs a break, and sometimes he gets himself into foul trouble. Josh is the best option to come in and relieve those guys, he is strong enough and plays with enough hustle to out rebound and defend guys much bigger than him.
TL

R = Don't be surprised to see Josh to play a lot of 4 and it not matter who starts as both will get their minutes.