I'd wait for
@amrutham to give a detailed reply although you have to understand the foundation of his trades before hand.
It is simple to explain but executing requires his skill, so let this part be clear.
Referring to his butterfly spreads, they are indeed entered on a directional perspective so if you cant do this properly you'll hit the wall more times than you want.
I assume most of his trades are be based on the highest OI on either side ( ie. Bullish & Bearish) then find a middle ground what can also be called Max Pain and try to center the expiry there and that would also be the center spot of the butterfly.
In spreads like butterfly etc, IV doesn't play much role with the bottom line, it is the Theta and underlying that's more important.
With bullish expiries he may prefer Call spreads and use Put spreads for Bearish expiries. Theta effect is highest on Mon-Tue for weekly BNO and that's where most of his trades originate.
Hope this explains a bit.