Untill he gets injured, both Sterling and Coutinho aren't exactly the most hardy of players, Sturridge also. I think you are vastly underestimating the loss of Suarez, especially since you have spent 100million on really very average players this window.
The problem at united is the Glazers, fucking Americans have caused us to spend 700million on debt repayments so far. No doubt Woodward is incompetent, who even knows is the huge amount of funds are available to spend like he claims (what idiot says this anyway). "Only Arsenal, of those English clubs to have competed in the Champions League during the Glazer era, have spent less than United". Which isn't bad considering the amount of trophies won in this period, however the squad is a shadow of itself and needs significant investment now. We will see what happens in the next few weeks and the January window, don't forget Liverpool lost last week 3-1 to this crappy squad as well (and Liverpool played a full strength available team).
What I do know is the friendly results under LVG compared to the ones under Moyes means that this season couldn't possibly be as bad as last. Not to mention the football being played is more fluid and skillful.
No ones going to beat Chelsea to the title this year regardless, their squad is just too strong, even with Mourinhos brand of snoozefest football.
LVG
Man Utd 7-0 LA Galaxy
Man Utd 3-2 Roma
Man Utd 0-0 Inter (won 5-3 on penalties)
Man Utd 3-1 Real Madrid
Man Utd 3-1 Liverpool
Moyes
Man Utd 0-1 Singha All-Star XI
Man Utd 5-1 A-League All Stars
Man Utd 2-3 Yokohama F Marinos
Man Utd 2-2 Cerezo Osaka
Man Utd 5-2 Kitchee
Man Utd 1-1 AIK
Man Utd 1-3 Sevilla
The different a decent Manager has is not to be underestimated. Moyes could never have achieved those results against the quality of opposition.