I would argue as above that this presents a false choice, but even so the example is hardly applicable because there aren't varying styles of javelin, just throwing it farther or shorter. Perhaps you could say adding the 3pt line, but even when that came out it wasn't really to accommodate existing styles and didn't affect the athlete scheme until a brief period about two decades later, which goes back to the false choice presented.
As far as injury concerns, new unanticipated injuries aren't uncommon. We could see less of the Malgin-Zacha injury only to see more injuries of the Harald Ofner nature. Players are bigger, faster, stronger as you said, changing the size of the surface won't necessarily make them safer.
You are probably totally right, let us just assume that. But for the sake of argument, or rather that I had some minutes to spend. Let me continue to discuss the topic a bit further.
I do not think we talk about different styles of ice sheets here, as little as I talk about different styles of Javelins. Javelins these days got modified so that they can't be thrown as far as an optimised javelin could be thrown. The same goes with the ice. It might be modified in order to decrease the likelihood of injuries. That can be done without even discussing types of ice-sheets.
It is a bit to extreme to talk about necessary conditions. At least as a theory. A condition A is said to be necessary for a condition B, if (and only if) the falsity (/nonexistence /non-occurrence) of A guarantees (or brings about) the falsity (/nonexistence /non-occurrence) of B. That can't be ensured as long as we deals with human interaction. So lets leave necessary conditions out of the discussion.
If we look at sufficient conditions then:
A condition A is said to be sufficient for a condition B, if (and only if) the truth (/existence /occurrence) of A guarantees (or brings about) the truth (/existence /occurrence) of B.
We can't say that a larger ice sheet can guarantee anything, that's for sure as long as we deal with human interaction.
But with an, say for the argument, infinite ice sheet we would reduce injuries as no one would find another player. We thus got a relative condition instead for an absolute yes or no. So it should be possible to assume that an increase of the ice sheet, how marginal it might be, should decrease the likelihood of players interfering with reach other.
Well, that's all from me on this subject, as I agree to assume that I am wrong (but not necessary or sufficiently though).
Game's up and work week tomorrow.