Hobbes: Remember as the attacker you not only delcare what your attacking, you also decide which attack happens when. Using you example you delcare that your attacking Egypt and blitzing with the intent for the tanks to reinforce Egypt. You then decide which of the attacks first, I.e. do the tanks blitz first then aid in the attack on Egypt (which IMOO, would be the better plan in your example) or do you attack Egypt first and then blitz congo with the tanks winding up in as the second move in the blitz.
Like I said unless your worried about losing the attack and thus too many troops to make holding the territory a bad idea, adding the tanks to to could help prevent this as they attack on a 3 or less.
-Ish
I think you misunderstood my point. The idea was that the UK makes 2 combat movements to Egypt and Congo and then moves the armor in non-combat from Congo to Egypt.