Not necessarily friend.
1. This list only calculates using revenues in US$.
2. Countries with huge "defense" (offense, actually) budgets like USA compared to their 'rivals' are bound to have more companies in the list. Even if country X, Y or Z has some of the most advanced scientific, industrial and technological basis but no political decision to spend much on military, not many companies from those countries will be on such lists.
3. USA, for example, finds a disproportionately high number of companies in this list because no Chinese companies are listed, because they 'extort' huge sums of money from idiotic despotic rulers in certain desert kingdoms for pretty much useless and downgraded weapons that can never be used against USA or even Europe. At the same time, most European countries, Japan, or similar countries spend much less on 'defense' than USA as % of their gov't budget because they are politically 'aligned'/'dependent' on USA.
4. US based firms are able to snare many more contracts from almost all countries around the world due to their strong media, propaganda and political departments. Examples are Rafale vs F-16 in Morocco. Morocco chose F-16 even though Rafale was better in almost every performance indicator simply because of American political 'clout'. France is not even half as powerful in global politics today. I reckon the same was the case in Singapore and South Korea.
5. Again, the problem with 'revenues' is that it only calculates the amount earned, not necessarily whether equipment provided by that company is necessarily of a higher quality than its counterparts. As a result, Dassault would earn 0 euro for selling 0 rafaleabroad, but Lockheed Martin/Boeing would earn billions for selling the much worse F-16/F-15 to Morocco, Korea or Singapore, perhaps.
6. I think Iranian, Kazakh, or maybe some Arab and similar firms were omitted from the list on purpose, as their earlier publications also did because they could not find data, or for some political reasons.
7. In short, this list is just an interesting list to pore over but one should not read too much into it.
You can read post #12.