Terrible display and result obviously.
Hoped things wouldn't be this bad. However this is where conviction is tested. If you want change, you need to keep believing and stay supportive in the bad times. Obviously there's not much positives to take from this. It would be silly to try to give this a positive spin. Nevertheless, many individual errors caused this.
First goal, you just can't coach that one. Last goal Maguire just lets his opponent run away from him, causing Martinez having to chase him rather than to occopy the space in the middle (where he could have intercepted the cross). The second and 4th goal are more results of a team that's work in progress. Obviously DDG shouldn't play the ball to Eriksen there, but this is something that can happen when you're trying to transition a team from long ball football to passing it out from the back (even when under pressure). Tough luck that this costs a goal now and this could happen more often, but in all honesty that's the things you have to go through if you want things to change like this. You don't change a counterattacking team to a tiki-taka team overnight without mistakes made. Mistakes, even if costly, are part of that process.
The goal conceded from the set piece is pretty much the same. Organization obviously was very bad there. Eriksen marking Toney is not the right set-up. After that Martinez makes the choice to cover the goalline but is then caught out when the ball isn't headed towards the far corner but squared. He's just out of position at that point as he decided to move backwards to cover the goalline and from there on he stands no chance to win that header. For me the Eriksen/Toney matchup is worse than Martinez making a choice that could have worked but backfired in the end. Moreover, it was also a good corner by Brentford. Nevertheless coaches will always view conceded goals from set plays as mistakes so I'm pretty sure this will be analized thoroughly so things will improve.
For me the most worrying thing was the total helplessness of the team in the first half. There was clearly also something wrong with the mentality / resiliance of this team. They were just overrun and didn't seem to have any fighting spirit. EtH clearly got angry at half time. The second half was much better. Granted that Brentford probably took it down a notch in intensity but they were never going to keep that up for 90 minutes anyway. Besides that United clearly had a different intensity in the second half themselves. United were much better on the ball in the second half and looked like a decent team, whereas in the first half United looked like a League 2 team.
Wonder what EtH is going to do now. This is obviously shocking and he can't have 4 results like this. On the other hand, stepping away from his plan so early doesn't bode well for the future. He'll have to find some kind of middle ground in which he can get the results in on shorter notice, whilst working on the long term plan as well. That may be a very difficult puzzle though.
I'll do a crazy prediction though, United will beat Liverpool next week.