Just checked my %'s for my one and only so far...
Cycle 50%, Run 30%, Swim 20%, averaged around 10 - 12 hours per week - is that classed as "very little", I guess it's all relative.
I also did as many hours strength training as I did in the pool. Personally, I think it helps prevent injuries.
If/when I do it again, I would do more cycling and less swimming. I am a crap swimmer so I needed to work on it for my first one
.
Looking back at my training, without singing my own praises too much, I was extremely consistent, and trained at least once a day, pretty much six days a week for 6 months 
Coming to ironman from a running background I was worried about the lack of run training, but I even managed to run a marathon about 4 months into the training, off the back of a longest run of 12 miles - so having a good all round fitness base must work