Is marathon a good idea?

I copy this from what Sweeney wrote in a thread I started but now hate: "Now it’s time to recover form the two beatings you took and plan for next year. I don’t know what your history is but you should make a plan now for next year. I don’t think a sept. or oct. marathon is a good idea for a triathlete. You should be trying to peak for a final tri at this time. Plan one of the winter or early spring marathons NEXT WINTER, not this winter! and use a training plan. There is one that looks interresting in this months issue of Inside Tri. You’ll need three months of running focus, running five days a week. The two key ingrediants are 50 mile weeks and twenty mile runs. The more the better. Train right and race smart and you will get beyond that 4:12 "

I’m what I would call a unstructured recreational triathlete (if that makes sense), and I’m probably the slowest on this forum. I live in Norway, with one or two small olympic distance triathlons each year (60-100). There are a lot of marathons but they are also very small (300).

If I am going to do a marathon next year I think I would go to Stockholm in Sweden or Cöpenhagen in Denmark (June or May).

But actually I’m considering building up my next season round a couple of half marathons in the spring, a 180 km bike race in late June and the olympic distance triathlons in August. Then if I have been a good boy, I might try and find a large olympic distance somewhere in Europe in september/october.

I must be doing marathons to prove something I guess, but for the time being I’m just trying to figure out if marathons fits in at all in my life. If I start focus on being better in olympic distance triathlons should I stop doing marathons or do they serve a function?