SQL JOIN으로 전체 직무 별 사원 COUNT

Amber's conglomerate corporation just acquired some new companies. Each of the companies follows this hierarchy:

Given the table schemas below, write a query to print the company_code, founder name, total number of lead managers, total number of senior managers, total number of managers, and total number of employees. Order your output by ascending company_code.

Note:

The tables may contain duplicate records.
The company_code is string, so the sorting should not be numeric. For example, if the company_codes are C_1, C_2, and C_10, then the ascending company_codes will be C_1, C_10, and C_2.

SELECT
    c.company_code,
    c.founder,
    COUNT(DISTINCT) lm.lead_manager_code) AS total_lead_managers, 
    COUNT(DISTINCT lm.lead_manager_code) AS total_lead_managers,
    COUNT(DISTINCT sm.senior_manager_code) AS total_senior_managers,
    COUNT(DISTINCT m.manager_code) AS total_managers,
    COUNT(DISTINCT e.employee_code) AS total_employees
FROM Company c
LEFT JOIN Lead_Manager lm
    ON c.company_code = lm.company_code
LEFT JOIN Senior_Manager sm
    ON c.company_code = sm.company_code
LEFT JOIN Manager m
    ON c.company_code = m.company_code
LEFT JOIN Employee e
    ON c.company_code = e.company_code
GROUP BY c.company_code, c.founder
ORDER BY c.company_code;