If it's business related ~sure they are open. They will exchange business cards.
If it's something else outside of business~the behavior varies.
See, the way you described it to be, isn’t the way guys would act normally. If they do think that it’s a strange girl in the sense they’ve never met before or just briefly, than they’ve almost certainly will not come on to you and ask your phone number. However, like Clement says if they do, than they’re self-confident but also with a lack of common decency. I can imagine why it would be strange to you, “what do they want with your phone number?”: One could ask herself. And it could be uncomfortable since it’s just something unexpected and you don’t want to make a big drama. It’s a (little) intimidating. I do not agree with they being assertive, someone’s assertive when they’ve would stand up for him-/her-self without being pretentious. But like you said: ‘foreigners’ (rather call it macho’s) not all of them, some of them, see an open opportunity to ask intimate questions when they sense the girl is shy or modest. Mostly they’ve elevated their male ego to act dominant, and think this impresses girls. I know most of men don’t act that way, but you have to think it’s a great opportunity when they’ve would inspired to do so, either with their low-social friends and with their tendency to just fantasize on having sexual intercourse with someone they do think the person’s just attractive and nothing more. If they’ve would just lean to much on bad influences and examples of friends, and imbalanced with contacts of the other gender, supposedly this would be the starting point for their behaviour.
Actually it is not just for foreign men, nowadays most of the men are very aggressive, they are self-confident and really assertive for what they want. The world has changed, fast food culture is totally replaced the old society.
I have never done this in my life. I would not dare to do that. If the girl herself somehow makes it clear she is interested I might do that, but never without a hint. In my opinion the courting must go both ways always. But yes there are some guys that do that.