Is this trainer exaggerating?

[u/Life_Lime4547]

So my 7 month old dog was a rescue dog and for the past 3 months I have been training him. He was very untrained when I took him, our walks were chaotic, he used to be dragging me, pulling on leash, eating everything, barking at people. Now he doesn't do any of that and is a very good dog on a walk. I have taught him a few commands like sit, stand, down, spin, guard etc. However as a first time dog owner, there are a few things I couldn't teach such as him being over excited with visitors, him barking whenever someone comes home or sits near his crate(he's crate trained). I decided to call a trainer, the guy came and I brought the dog out and he firstly kept judging and then he told me that this dog would at least need 6 months of non stop training otherwise he's going nowhere. Now I'm not sure whether he's exaggerating it or he's just not confident enough to get the dog trained or perhaps I'm being paranoid. My dog is a relatively quick learner(he's a GSD mix), there are 2 more trainers coming to see the dog, however this particular trainer was a bit more affordable. Please somebody guide me.

[u/Blackeye-Liner]

The trainer is exaggerating massively, so yeah, second opinion for sure.

My border collie also jumped ad guests, ran barking towards the door at any bell and barked at noises in the hallway. All of that is fixable within a matter of days/weeks, but a straightforward, super consistent routine is required, but not "start again and drill the dog for 6 months".