I might have made it this way intentionally so that the AI would be more likely to resolve stalemates. However, there are better ways to do that. At the very least this makes the AI biased to resolving stalemates with vehicles, which is sub optimal. This might also make the AI less effective at taking opportunities.
Ultimately, this bug can wait since it doesn't break anything, and is only noticeable in specific scenarios. Hence, I have given this the low priority.
I might have made it this way intentionally so that the AI would be more likely to resolve stalemates. However, there are better ways to do that. At the very least this makes the AI biased to resolving stalemates with vehicles, which is sub optimal. This might also make the AI less effective at taking opportunities.