Some traditional family arranged marriages (like muslim ones) get married on the first meeting without courtship or dating. This is because pre-marriage (or extra-marriage) relationships are not acceptable and the relationship typically starts after marriage declaration. I wonder how the CIC looks at these. I think they know these things but you know to provide overwhelming evidences. The CIC cannot use the criteria of courtship on judging on these relationships.
Therefore, length of courtship is variable and depends on your country/origin. Your individual circumstance are other controlling factors.
If the courtship is short, you have to defend this on your statement and make sure that you overcome this point by other strong evidences.