Know exactly what you mean, I thought that it was a really big gap and I also disliked the lack of viable offensive foot units in early industrial era. Which also got me thinking that all the industrial foot units are almost never a good offensive choice which I though was totally inaccurate. So I have been putting together my own little mod which fills in some gaps and adds a lot more action on the ground.
Added a new gunpowder foot unit: Man-At-Arms (5/2/1)
Available with Navigation, requires saltpeter. Medieval Inf. upgrades to Man-At-Arms, and will upgrade later to Guerilla (Replaceable Parts)
Added a new def gunpowder unit: Grenadier (3/5/1)
Available with Metallurgy, requires saltpeter. Musketman upgrade to Grenadier and will upgrade later to Trench Infantry (Industrialization)
Rifleman redone with (6/5/1), same advance and no reqs, but in order to research Nationalism you must 1st research Imperialism (Gov tech)
Added Trench Infantry (4/6/1), available with Industrialization, no resource reqs and will upgrade to Machinegun Battalion (Rep Parts)
Guerilla redone with (7/7/1 all terrain as roads), same advance and no reqs and later upgrade to Grunts (Syth Fibers)
Infantry redone with (10/8/1), same advance and rubber req and later upgrade to Modern Infantry (Syth Fibers)
Added from WWII C3C scenario MG Battalion (6/10/1) requires Rep Parts and rubber and later upgrades to TOW Infantry (same reqs)
Added from WWII C3C scenario Combat Engineers (12/8/1) requires Radio (back in) and rubber and later upgrades to Modern Infantry.
Added new artillery unit Howitzer (14bmb, 2rng, 2rof, 1move) that Cannon now upgrades to: requires Rocketry, no resource and will later upgrade to Radar Artillery (same reqs)
Added new modern unit Grunt (10/10/1 all terrain as roads), requires Synth Fibers and no resource.
Added new modern unit Modern Inf. (14/10/1), requires Syth Fibers and rubber.
Along with a bunch of other little tweaks:
Oligarchy and Imperialism tech and govs
Naval changes (movement changes and more balanced middle ages/industrial attack/def values)
Civ strength tweaks (Expansion builds Migrants instead of Settlers, same sheilds, 2 movement points, only 1 pop point; Non-seafaring civs can no longer build Curraghs, Japan's Samurai now replaces Medieval Infantry)
Graphic changes - Used Snoopy's grenner, plus a bunch of misc extras like irrigation, pop faces, wonder splashes, etc.
And more but I forgot! lol
Maybe if there is some interest in it I'll post it but it's not really a redesign of C3C, just some good tweaking that I think plays much more smoothly.
Here are some shots:
Middle Ages Tech Tree -
http://www.crst.net/tmp/ma_techtree.jpg
Industrial Tech Tree -
http://www.crst.net/tmp/ia_techtree.jpg
Modern Tech Tree -
http://www.crst.net/tmp/mod_techtree.jpg
Unit: Man-At-Arms -
http://www.crst.net/tmp/unit_man.jpg
Unit: Grenadier -
http://www.crst.net/tmp/unit_gren.jpg
Unit: Trench Infantry -
http://www.crst.net/tmp/unit_trench.jpg
Unit: MG Battalion -
http://www.crst.net/tmp/unit_mg.jpg
Unit: Combat Engineer -
http://www.crst.net/tmp/unit_ce.jpg
Unit: Howitzer -
http://www.crst.net/tmp/unit_how.jpg
Unit: Grunt -
http://www.crst.net/tmp/unit_grunt.jpg
Unit: Modern Infantry -
http://www.crst.net/tmp/unit_mi.jpg
Gov't: Oligarchy -
http://www.crst.net/tmp/gov_oli.jpg
Gov't: Imperialism -
http://www.crst.net/tmp/gov_imp.jpg
Terrain -
http://www.crst.net/tmp/terrain.jpg
Units in game -
http://www.crst.net/tmp/units.jpg