Loud and Quite: Margin / Grid making

Loud and Quite is a free tabloid newspaper and exactly the same size as the newspaper I will be printing. I thought it was a good idea to see how another free tabloid aimed at a similar market is designed and how the grid works. Looking at different margins, columns and bleeds. 

Looking at this paper, it surprised me that simple rules of the grid are not applied. On some spreads the margins on either size are un-even and inspecting it with a ruler I feel it looks un-professional and just wrong.

Decided grid:

The document is 12 pages, 289x380mm, with a 15mm printing margin.

I have chosen to make the guide margin at 25mm. 
6 columns (so it can be 2 column, 3 or 6 equal) with a 10mm gutter.

Using a 12pt baseline grid. setting up a baseline grid in InDesign