No, this is not a good idea. The resources that they have are pretty good. You get those that give food, those that give shields and food, those that give shields, those that give food and money, those that give shields and money, those that give money. If you want more resources in Civ3, all you have to do is go to the thread for Customization and Creation in this thread.
I love what Civ3 did with resources (especially the strategic ones). There may be tweaks that I thought could be better, but on the whole, they made major leaps beyond what Civ2 had!