The way it was expressed indicates that everyone could exchange coins for shares of the ARCH company with 1:1 ratio, but perhaps there will be a minimum required.
The reasoning behind this is simple, accounting-wise it would be hell on earth for those in charge to keep numbers on track if, for example, we would have 16M shareholders (as if every person would want to get 1 share of ARCH for 1 coin only). Therefore logic indicates that perhaps for example "packets of 1,000 coins" could be used at the time of the swap for "packets of 1,000 shares".
Again, for the sake of the accountants and the health of the books.
Just MY personal thinking, it does NOT reflect an official answer at all, just brainstorming here.
Surely BTCA or other admin member will come back with a clarification soon.
Eth.