Output of 'select * (with order by limit) queries' returns unexpected result

1. simple table created. 4 rows of data is entered.

CREATE TABLE `football_teams` (
`num` int(11) DEFAULT NULL,
`name` varchar(32) DEFAULT NULL,
`roster_size` int(11) DEFAULT NULL
) ENGINE=Columnstore;

insert into football_teams VALUES (1,'Green Bay',53);
insert into football_teams VALUES (2,'Chicago',53);
insert into football_teams VALUES (3,'Detroit',53);
insert into football_teams VALUES (4,'Minnesota',53);

MariaDB [test]> select * from football_teams;
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2. A query that orders the entries by a column and limits the return. This output is as expected.

MariaDB [test]> select distinct num from football_teams order by num limit 3;
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3. subquery result set is not equivalent with result in step-2

MariaDB [test]> select * from (select distinct num from football_teams order by num limit 3) a;
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