There's a reason that no-one plays 2/3/5 anymore.
The best way to space players out in the defence is to cover the back line with four players. We haven't been losing at home because of the number of defenders we have on the pitch, we've been losing because of the mistakes they've been making. With regards to play attacking football - you don't have to have x number of players playing as 'attackers' to play attacking football. A 4-4-2 formation is no bar to playing attacking football, it just depends on what players you pick and how you go about the game.
Conversely, playing the formation Renegade suggests would lead to certain defeat. I don't even think that we'd score many goals playing like that.
-----------------------------------------Esson---------------------------------------------------
-----------Tokely-----------------------Munro-----------------------McBain-------------------
-------------------------------------------Cox----------------------------------------------------
---Hayes--------------------------------Imrie----------------------------------Djebi-Zadi-----
----------------Sanchez--------------Barrowman-------------Foran---------------------------
Three central strikers playing in between two 'wide' men? One of the keys to opening up opposition defences is making intelligent runs into space. There wouldn't be any space to exploit given that we'd have three players playing across the middle. None of these players would be used to playing in this way with two other strikers in the central area so building understanding and good interplay between the forwards would be very difficult.
Also, with this formation you are effectively surrendering the midfield by having one player sitting back (in thsi case Cox). A single player couldn't physically cover the area required and he would be overrun. Hayes and Djebi-Zadi already have to cover the entirity of the flanks so asking them to tuck in when required would be unrealistic.
Defensively it's obvious that any team playing this formation would concede a lot of goals. Three central defenders is a discredited system that is barely used anymore at the top level of football, it's easy to pick apart by attacking wide areas. In this formation this tactic would be especially devastating - play a ball into the wide area (where you'd normally expect a full back to be) and pull one of the central defenders wide. This would expose space in the middle of the defence for opposition forwards or midfield runners to exploit. The defensive system would also have the flaws of the attacking system, in that our defenders have no experience of playing in a back three with no full backs or wing backs. The obvious outball for a central defender is to lay off to the full back, that's taken away in this formation. In fact, what playing this way would lead to is far more long balls simply because there isn't anyone to pass to on the rare occasion when our defenders would get the ball (rather than pick it out of our own net).
I don't normally go into detail on Renegade's crazy scheme's but it's worth doing so simply because people seem actually to be giving credence to these fantastical ideas as a potential system toplay! Literally, incredible stuff.