As many times 5v5 pug fails to fill, as sometimes due to lack of 2 players or 4 players.
So its suggestion to add 3v3 and 4v4 pug also just like 5v5 and 6v6. So those who want to play pug games can play it daily and it will also attract more players. Because players those players who play daily will keep it up.
In mapvote there is free build maplist which can be replaced also. There are also some small maps for 3v3 and 4v4. It will be fun.