I've sometimes wondered about this appropriation of sites, particularly in the case of nearby (to me) Lewes which has three prominent mounds, two of which are mottes for Lewes Castle, unusual in itself, but it all makes perfect sense.
'We only did The Mount (The Tump) in Lewes, but would dearly love to have investigated Brack Mount too. I don't think we will do it now, as part of this project, but the technique we use is relatively straight forward (and relatively cheap when compared to excavation costs) so I'm hoping others will follow suit. If not perhaps a Round mounds round 2 is in order!'
That's a shame as I think Brack Mount would have yielded more information as a partial excavation in 1838 uncovered an inhumation and boar's skull.
As you say Sherrington also looks very promising and, according to a couple of archaeologists I was working with earlier this year, the Wylye Valley is probably going to come under a lot more scrutiny in the near future as it was an easy access to Salisbury Plain and Stonehenge.
You emailed him, how sensible. Let's hope someone gets the money to have a look - I guess now they are showing it's definitely worth doing the research, it'll be easier to put in for a similar project? Lewes castle looks interesting, I've not been there. Your Brack Mount has the advantage of not having a massive lump of stonework on top of it too.