Very impressive! Two months is definitely more than I could stand to spend on a unit of eight models but you've done it and the unit does look great as a result.
Since you've asked for C&C, let me raise two points about the plumes and the lances. The pictures perhaps don't do the plumes justice, but they look like they were drybrushed a dark red over a black basecoat. There is nothing wrong with that in itself, but it does look like you spent relatively little time on them compared to the rest of the models. I think that you could really elevate the overall look of the unit if you take another crack at the plumes. I'm thinking red-and-yellow and high contrast like you did on the shields and flag.
Secondly, the lances. I think they'd look better painted red entirely. The yellow stands out so much that it draws the eye towards the rear of the lance, which isn't a very interesting place on the model. The black and yellow part in itself certainly doesn't look bad but I think there are better places to add yellow to the models, like the plumes or on lance pennons if you chose to add them. Also I'd paint the flagpole red too to tie the standard bearer in with the rest of the unit.
I hope this is helpful and of course none of this C&C detracts from what is a very good-looking paint job!
Thanks for the comment and the observations! I appreciate someone taking the time to analyse the paintjob and commenting on it.

Now, covering the points you make:
-You're right, the plumes are drybrushed mostly because I wanted the unit to be painted at a high level but didn't want to spend much more time on them, to be honest. It's true that I could have taken more time with them, and even thought of the bi-colour option, but I ruled it out mostly because I wanted to get the unit out of the way as soon as I could and have my 2K list ready as soon as I can.
-The lances being bi-colour have to do with the above. I wanted to make them look different enough from the Reiksguard, so that's why I added yellow knowing I couldn't be bothered to get the plumes more detailed (and you're right, it could have been a nice option)
Painting a whole unit with NMM will make looks go there. NMM, face (preceptor), black NMM barding, shields. The yellow on the smaller part of the lances won't stand out too much because it is only a small bit which is only visible from a certain angle whereas the overall look of the unit remains the way I intended it to be. One thing I've learned during all these years painting is that looks always go towards advanced techniques, OSL, NMM, glazing, faces (gradient).
Thanks again for the comment : )