Depending on how big the race is, try to get a spot very near the front. If top 5 percent means you should be in the first two rows, then by all means, get in those first two rows. You are not doing anyone a favor if you start way back and have to weave/maneuver your way through the field. Just because someone thinks it is not "fair" to jump to your place in line doesn't mean you should put yourself and others at risk.
If top 5 percent means you should be more like row 10 or 20, it gets a little more complicated. You don't want to start way back, but you also don't want to start too far up and be a hazard to the top of the field. If possible, try to slide in on the edge at your proper place.
I was at a local road race recently and encountered a similar situation - but luckily, a couple friends and I (who were warming up with me) have run this race numerous times, and being recognized helped us get our place. As we were walking up after doing strides (3 or 4 minutes before the race started), the race director was announcing, "If you are just getting to the line, move to the back of the crowd!" But when she saw us eyeballing the situation, she added, "Faster runners to the front! Make sure to let the faster runners to the front!"
Hopefully your race is similarly sensible in letting faster runners to the front, and hopefully you fit the bill (both in appearance and performance) as a "faster" runner for your race.