订购多表县查询

I have a query that targets several tables, each of which has its own unique numerical key named N. For example, Table 1 might be numbered 1-2034, while Table 2 is 1-10,488. I'd like to know if there's a way to order the results, so that everything in the first table queried displays in numerical order, followed by everything from the second table, etc.

This particular example is confusing because the table gz_life_mammals is queried twice. If possible, I'd simple like to treat it as two different tables, with the results of the first query (field Taxon AS URL) listed first, followed by the results of the next query (field Slug AS URL).

SELECT URL, SUM(c) c
FROM (
 SELECT URL, COUNT(*) c FROM gw_topics GROUP BY URL
 UNION ALL 
 SELECT Taxon AS URL, COUNT(*) c FROM gz_life_mammals GROUP BY URL
 UNION ALL 
 SELECT Slug AS URL, COUNT(*) c FROM gz_life_mammals GROUP BY URL
 ) AS Combined
GROUP BY URL
HAVING c > 1