Nurse,
Unfortunately the end user for the 8 Mk3s is different to any potential Mk2 upgrade. Therefore, they are on a different timeline. However, it would be common sense to de-risk the Mk2 MLU with the Mk3 Fix-to-Field as much as possible to minimise recurring costs.
Nice idea to replace CH47 with AH64 for Royal, but I don't think we have the required 60 odd AH at first line to conduct a company lift! Still, we could exhume the ACH-47 and have the SH escorting the AH....!
Electric sheep, IMHO you're bang on - we have no spare ac to "prime the pump" for a future MLU - we'd need a substantial reduction in Op tempo to achieve it without severely reducing ac available to the front line.