How broken does it have to be?

I attended another single day 40k tournament last weekend and I was planning on doing a full battle report but in hindsight this probably wouldn't be the most riveting read. The reason for this was simply down to how I built my list and what it contained. My plan for this tournament was plain and simple, I had 2 sentry pylons on the shelf which I've only ever used once and never really tried them so it was a good excuse to dust them off and finally get them painted. I also had a tomb citadel which has only been used twice in the 12 months I've owned it and it was still unpainted..... A couple of days before the tournament I got the airbrush out and managed to get them finished so knew I wanted these in the list. I also knew that the tournament itself allows 2 sources so it was list building time. Realizing that it would end up being a small model count list and then decided to make it into a challenge for the lowest model count I could muster while still being able to hol