I was wondering recently how many industries of each type does one need while using both mods in order to get a good balance and as little over-/underproduction as possible. RIC alone offers a nice, ordered list of required facilities: 8 regular farms, 4 advanced farms, 12 oil wells etc. However, IE makes certain changes to basic industries' output, for example a farm produces 300 grains instead of 200 and coal mine ships 600 units instead of 400. This as well as the new chains breaks the balance, so I've spent some time calculating and come to the conclusion that the most optimal system consists of a total of 331 industries (excluding mail), producing 4800 units of each end product (in case of fuel 4800 units being left to ship to cities after supplying other factories).
331 facilities correspond to very high industry density on a huge map or slightly above medium density on a megalomaniac map; a similar town density results in about 40 cities, meaning an average of 210 units of an end product per town (which is why I'm also using More Industry Levels).
Here are the numbers of industries:

• regular farm: 24
  
• advanced farm: 8
  
• livestock farm: 6
  
• food processing plant RIC: 2
  
• food processing plant IE: 3
  
• packaging factory: 10
  
• plastic factory: 12
  
• bioplastic factory: 7
  
• forest: 33
  
• saw mill: 18
  
• oil well: 44
  
• oil refinery: 22
  
• oil sands: 4
  
• fuel refinery RIC: 25
  
• fuel refinery IE: 3
  
• tool factory: 4
  
• industrial tool factory: 6
  
• machine factory RIC: 2
  
• machine factory IE: 2
  
• silver mine: 6
  
• silver mill: 4
  
• coal mine: 15
  
• iron mine: 15
  
• steel mill: 11
  
• distillery: 1
  
• fishery: 3
  
• coffee farm: 3
  
• coffee refinery: 1
  
• meat processing plant: 2
  
• lubricants factory: 7
  
• quarry: 3
  
• construction material plant RIC: 2
  
• construction material plant IE: 3
  
• marble mine: 2
  
• goods factory RIC: 2
  
• goods factory IE: 6
  
• paper mill: 2
  
• waste management plant: 8

I did not include mail sorting centers since they don't interact with other industries, but I assume 1 or 2 per each waste processing plant should be enough.