Array of functions not working when called in object

So I'm working on what should have been an easy project but is giving me, my classmates, and my mentor a ton of headaches. We're nearly there but it's still missing one piece to finally wrap it up. I just need to get the fact area to fill out with one of the function options.

Here's the function:

function createHuman(){
  let height = parseInt(humanFeet) * 12 + parseInt(humanInches);
    debugger
    myNewHuman = new human(humanName, "human", humanWeight.value, height, humanDiet.value, compareRand);
    function compareWeight(humanWeight){
      let myRandNum = Math.floor(Math.random() * dinoArr.length);
      let myMessage = `You are ${dinoArr[myRandNum].weight - humanWeight} pounds lighter than a ${dinoArr[myRandNum].name}.`;
      return myMessage;
      };
    function compareHeight(height){
      let myRandNum = Math.floor(Math.random() * dinoArr.length);
      let myMessage = `You are ${dinoArr[myRandNum].height - height} pounds shorter than a ${dinoArr[myRandNum].name}.`;
      return myMessage;
      };
    function compareDiet(humanDiet){
      let myRandNum = Math.floor(Math.random() * dinoArr.length);
      let myMessage = `You're a ${humanDiet} while ${dinoArr[myRandNum].name} is a ${dinoArr[myRandNum].diet}.`;
      return myMessage;
      };
  const compareRand = Math.floor(Math.random() * compareArray.length);
  compareArray = [compareWeight(), compareHeight(), compareDiet()]; 
};

Individually the functions work fine when placed like this , compareWeight(humanWeight.value) where compareRand is right now and the results should look like this: Screenshot of example of one function working in the facts area. I would post a screenshot of all the dinos around the human tile but that's too big for stackoverflow.

I'd really appreciate any input anyone could give me so I can finally finish is project.

(Please note: the dinoArr is an array outside of this function pulling data from a .json file. As the screenshot shows it's pulling the data just fine I just need to get the random picking of the array of functions to work.)