Both "has" and "have" sound ok to me here as a native speaker. Both of these can describe the same event: - The cows have 10 seconds to enter the field - The

Both "has" and "have" sound ok to me here as a native speaker. Both of these can describe the same event: - The cows have 10 seconds to enter the field - The herd has 10 seconds to enter the field In the case of "crew", the word can either mean - The people who are part of the crew (like "the cows") - The crew as a collective unit (like "the herd") Which is why both sound ok