I have some suggestion.
unique t4 infantry for each faction
1.China :Cyborg Vanguard
requires Soviet Barracks+Atomheart+Industrial Plant
2.Russia :Voltmotar without cloaked ability
requires Soviet Barracks+Palace+Industrial Plant
3.Latin Confederation :Bomb Bike (may be buff with bomb that cause ground to catch fire like an Arsonist napalm charge but lesser damage)
requires Soviet Barracks+Battle Lab+Industrial Plant
4.Pacific Front :Cryo Commando that cannot attack building with Personal Thermal Inversion cannon (may be buff with ability to attack structure with cryobeam(weaker than cryocopter))
requires Allied Barracks+Robot Ops Control Center+Tech Center+Experimental Warpshop
5.European Alliance :Chrono Legionnaire
requires Allied Barracks+Shield Command+Tech Center+Experimental Warpshop
6.USA :Hoplite or Prism Hoplite
requires Allied Barracks+Mercury Uplink+Tech Center+Experimental Warpshop
7.Epsilon Headquarters :Reaper
requires Epsilon Barracks+Pandora Hub with Geneplug+Cloning Vats
8.Scorpion Cell :Virus (may be buff with Multiple Virus shots affect infection rate)
requires Epsilon Barracks+Pandora Hub with Chemplug+Cloning Vats
9.PsiCorps :Acolyte (new unit and may be use old MO 3.0 suppressor model graphic)
weapons:Personal Psychic Decimator,Magnetic Field(deployable)
abilities:immobilizes enemy vehicles and infantry vulnerable to magnetic weapons when deploy(range 3),amphibious,cannot attack flying unit,good vs infantry and light armored unit
purpose:anti-infantry,unit immobilizer
requires Epsilon Barracks+Pandora Hub with Psychplug+Cloning Vats