It's been a while since you wrote that message and you've probably figured out what to do by now, but yes. With this built, there won't be enough iron for all the production. As i stated above, i'm new to this game and have been playing for 65 hours. After multiple revisions to the production line, i found that Having multiple iron mining and smelting areas with 10 or 20 furnaces and distributing irons evenly by using balancers is only good option.
Also, i don't know if it's just me but i think world generation in this game is little buggy and needs some adjustments. None of the presets seem to have no affect whatsoever. For example, i created a few worlds by selecting Rail World preset and resources were so close to each other. If you change settings to very low frequency and small/very small size, game fills the map with trees.
Game is still EA tho. I hope they'll make some adjustments.
The rail world preset doesn't affect the starting area, so you have to venture out quite a bit before seeing its effect. If you're not happy with rail world, try the mod RSO (resource spawner overhaul), which does a similar thing but I believe it has greater distances and larger resource fields.