Merge Sort - Sorting String Array with Int Array

For this project, I'm given an array of strings and an array of ints. int[1] is the ranking for string[1]. I need to sort the int array in order from 1 to n using mergesort, which I've done below. But I also need to switch the positions of the string array when the int array gets moved so they are both sorted, if that makes sense? I can't figure out what's wrong with my coding or even if my idea will actually work, but I keep getting an array index out of bounds error on stringSorted[k] = stringRight[j] and I can't figure out if there's a way to fix this. Essentially, when an int was added to the sortedInt array, I also added that element to the sorted String array. Thank you for any help, and let me know if something doesn't make sense

private static int sortAndCount(int intToSort[]){

    int inversionsLeft;
    int inversionsRight;
    int inversionsMerged;

    if(intToSort.length == 1){
        return 0;
    }

    int m = intToSort.length/2;

    int[] intLeft = new int[m];
    stringLeft = new String[m];

    int[] intRight = new int[intToSort.length-m];
    stringRight = new String[intToSort.length-m];


    for (int i=0; i < m; i++){
        intLeft[i] = intToSort[i];
        stringLeft[i] = stringToSort[i];
    }

    for (int i = 0;i < intRight.length; i++){
            intRight[i] = intToSort[m+i];
            stringRight[i] = stringToSort[m+i];
    }

    inversionsLeft = sortAndCount(intLeft);
    inversionsRight = sortAndCount(intRight);

    intSorted = new int[intToSort.length];
    stringSorted = new String[stringToSort.length];

    inversionsMerged = mergeAndCount(intLeft, intRight);

    return(inversionsLeft + inversionsRight + inversionsMerged);

}

private static int mergeAndCount(int[] intLeft, int[] intRight){

    int count = 0;
    int i = 0;
    int j = 0;
    int k = 0;

    while(i < intLeft.length && j < intRight.length){

        if(intLeft[i] < intRight[j]){
            intSorted[k] = intLeft[i];
            stringSorted[k] = stringLeft[i];
            i++;
        }

        else{
            intSorted[k] = intRight[j];
            stringSorted[k] = stringRight[j];
            count += intLeft.length - i + 1;
            j++;
        }

        k++;

    }

     while (i < intLeft.length)
        {
            intSorted[k] = intLeft[i];
            stringSorted[k] = stringLeft[i];
            k++;
            i++;

        }

     while (j < intRight.length)
        {
            intSorted[k] = intRight[j];
            stringSorted[k] = stringRight[j];
            j++;
            k++;

        }

     return count;

}

}