How to check if inspector-filled array is empty

Hello! This is probably the easiest question ever, but I'm stuck, so any help would be nice.

I have an array that I fill out in the inspector with values. It's an array of my own Serialized class. In that class, I have another array of the same class. Like so:

 [System.Serializable]
 public class RoundInfo
 {
     
     public RoundInfo[] MetaRound;

Now I want to combine these multiple arrays into 1. There will always be at most 2 arrays to combine, so it shouldn't be a problem. Here's the code for it:

 if (Rounds[currentLevel].MetaRound.Length > 0) // Convert 1 Round Info and 1 array of Round Infos into 1 array
         {
             currentRoundInfo = new RoundInfo[Rounds[currentLevel].MetaRound.Length + 1];
         }
         else
         {
             currentRoundInfo = new RoundInfo[1];
         }
         
         currentRoundInfo[0] = Rounds[currentLevel];
         for (int i = 1; i < currentRoundInfo.Length; i++)
         {
             currentRoundInfo[i] = Rounds[currentLevel].MetaRound[i];
         }

However, it gives me an "Array index out of range" when trying to access MetaRound on line #1, when MetaRound is empty in the inspector. I need MetaRound to be able to be empty.

I'm guessing it's because it never gets initialized. But how can I check if it's empty, if Length > 0 doesn't work? If I set it through code, this works like a charm, but since I need the inspector (1000 times smoother to work with)... well.. it's a bitch.

I've come up with 1 way to work around it, and that's to use a List instead - but is it really necessary?