I see how he's come to it. However, that's not the same as...
"José Mourinho has been told that he will have to work with Tottenham’s existing squad as there is no money for an overhaul in January."
There's been nothing from the club indicating that to be the case. He's probably been told that money's not water and we aren't going to be throwing the stuff about, with the Academy a primary source of replacements but I can't see the club being that hard line at this point. This is 2+2 reporting.
One could equally suggest that needing, at least, 2 centre halves, a couple of full backs and a holding midfield player, and having £60m or so of income at risk if we fail to qualify for European football, the club might re-draw its budgets to plug some of those holes in January.
It's what we did in 2007, buying Woodgate, Hutton and Gilberto at considerable expense on top of a net spend in the summer window. We have enormous potential in FFP spend and have just significantly re-jigged our debt. If we want to spend and can negotiate deals for the right players, the money could be found, if we're still struggling come January. If that's the case, I reckon that logic and the existing budget will go out of the window, somewhat and we'll try to bring players in.
Attracting a stadium sponsor and keeping HK, Sonny and our other assets is going to be much harder if we're sitting on our hands on Tues, Weds and Thursday nights in 2020/1.