Sum, you are correct that a higher offer would not allow the fund to tender at the lower price. The fund would actually be pleased by this development. But in the end, if there are two competing offers that are similar (or a matched offer) then the funds can "recommend" that of the two equivalent offers, a certain offer would be favored.

OR, since there might be a time lag before a competing offer came in, the fund could tender to the first offerer fairly expeditiously. At this point, the accumulation past 10% or 20% would be irrelevant.

Also remember that the concept of "Noront's package being too big to let go of" may not be relevant for a global giant. For example, there has been some debate about whether a large company like Xstrata would start a bidding war with Cliff's if Cliffs made an offer for KWG. I believe that Xstrata would have another option: to just sit back and let it happen, and a year later, buy Cliffs. So if Noront was about to be swallowed by a bigger fish, an even bigger fish than both might not bother fighting, but rather wait and swallow the combined entity.