Of course they're smart. This is their business. They want to do this, 100%. This is not a hard code to crack, obviously.
The only way you're going to be able to make sure that none of those foreign funds get into the election orbit at all is to absolutely enforce a separation of accounting, wherein all of it goes into this fund over here and is not allowed to cross-pollinate with any money that could legitimately be used for regulated expenses.
Now, groups would be affected differently by this, obviously. A lot of groups that act as third parties in elections have whole other lives, with whole other services they provide. They might have entirely legitimate reasons to receive funds from outside Canada in order to do whatever their operations are, whereas some third parties probably have no interaction at all in their operations with foreign entities. They would get no foreign money for legitimate reasons. Putting the onus on third parties by saying, “You have to keep your money separate”, and thinking that this is important enough.... It's a loophole, 100%.