See we will go by your method using complements. See total ways are $720$ . now lets group three men so let us assume them $x$ . now let us place them in positions $123$ so total ways are $3!.3!=36$ as men and women can e arranged amongst in $3!$ ways. Now place $x$ at place $234$ again same number of ways ie $36$ now similarly at $345,456$ so total ways become $36\cdot 4=144$ now group any two men . this can be done in $3$ ways. Place them at place $1,2$ now total ways become $3.2!.3.3!=108$ . men can be arranged in $2!$ ways $3rd$ place has to be female or it becomez similar to $3$ men together so $3$ ways and $1M,2w$ can be arranged in $3!$ ways. Note that now they cant be placed in positions $(23),(34),(45)$ as it becomes similar to $3$ men together. So now they can be placed at $56$ position. Again similar to $12$ position we get $108$ ways . now remember we are talking complement of total permitted ways . hence total ways are $720-144-216=360$