I don't think we could play 90 minutes with the 4 attackers together, as Pickles says, we world be too open in MF, I think it works better later in games when defenders are tired and for a short period we can overwhelm them.
Having a fresh 4th attacker on the bench who offers a real goal threat (Unlike Origi) and can change a game is a great asset to have, so we can replace a tiring attacker and give the opposition something else to worry about, giving us the option to change our attack.
For too many games earlier in the season, it seemed we were just doing the same thing again and again and it was not working, with no ability to change it, repeating the same pattern when we went behind to a lesser team, we had become predictable and did not have the ability to change, probably due to lack of key players/options and confidence.
Bobby still has a role to play, but more a squad player, to change things and freshen things up, as well as still being a starter like at the weekend, we now have 4 players capable of playing the front 3 roles, which is something we have lacked for a long time and we just hoped the front 3 stayed fit/in form.