C and C++ are definitely the fastest languages you can find on Codingame. That said if you look at the leaderboard we can find javascript in the top 20, python 3 in the top 30 while the first C user is above 30. So even without heavy simulations you can still be relevant and competitive.
42 of top 50 bots were in C/C++/C# despite having almost the same amount of bots using python language.
This is very biased as most top contenders (and likely the coders with most experience) will use/learn the best language that is available to increase their chance to win the contest while Python/Javascript/Java /C# users are often more casual (or even beginners). I am pretty sure that most top 50 members could switch from C++ to Java or even maybe Python and still be in the top 100. Above top 100, performances are usually not an issue and it all comes down to the best heuristic which is easier/faster to code in Python.
In my opinion nerfing C/C++ wouldn’t affect much the overall ranking but mainly result in less “intelligent” top bots.