I don't play brits but I would say that having build orders in general is a waste of your time. Yeah units like infantry sections are in general good units to have but decisions like whether to get a sniper should be based on what you're facing. Should I get one in the early-mid game if my opponent has been able to hold multiple fuels? Probably not. Do I need suppression? Is their style static or fluid? What is the reinforcement cost of their infantry choices? All bullshit you should take into account when you're playing because your income is fought for and there's no such thing as a best build order.
I agree its situational thats why my thread is titled opening build this indicates the first 3- 4 minutes of gameplay.. firs 3 units that you call can still be situational depending on map and spawns but the safest / efficent opening is what i was after..