Moving into an assault hex

[leonard]

2x disrupted T-34's in assault hex, 2 more (good order) outside. 1 T-34 moves to join the 2 disrupted ones. When the good order T-34 moves in, and attack, may the 2 disrupted T-34's join the assault? Rules in question 12.3 and 12.51.

Under Fire in the steppe tank leader rule ? Nice puzzle.
I was first wondering if 12.51 holds for tank leaders or not.
Even if OK, wouldn’t it require the use of two tank leaders during the same activation : one inside the assault and one outside ? Strange enough. More questions than answers....