I think more variety of elites or common grunts will be great to spice up gameplay and add more challenge by not making "terminator" grunts but different types of enemies what can synergize with eachother.
So lets start:
Soldier with DMR - armed with powerful and accurate semi auto rifle , this enemy is hybrid of elite sniper and common grunt , he is most effective at medium range. Slower fire rate , better accuracy at mid range and higher damage comparing to his common grunt friend. Not effective at close range due slow fire rate and have accuracy penalty at long range , making snipers better at long range. Same health as common grunt.
Soldier with riot shield: Armed with shield and pistol , this enemy is very hard to deal in direct firefight but vulnerable to flanking. All damage from front side is reduced by 95% and cant be grappled or punched. Can attack with shield in CQC , staggering and pushing his enemy. Very slow and vulnerable to attacks from sides and back. Can be grappled from back and sides , instakilling him and can be pucnhed from sides and back. Very low pistol and CQC dmg. High amount of health.
Heavy machine gunner: Armed with HMG but need to be deployed to fire from it. Acts like current soldiers with RPG , using pistol while moving. When in cover can deploy his HMG and lay down supressive fire. Low damage but can fire for long time with its large mags. Same amount of health as RPG soldier.
Medic: Support unit what can heal nearby comrades. Can create healing circle what heal all units its range.Armed with same weapon as common grunt. Same health as common grunt.
High MMR version: Elite medic with same abilities BUT also can apply damage reduction to his comrades.
Combat engineer: Support unit what can place portable turrets and spawn drones or miners(have cooldown with each spawn). Armed with same weapon as common grunt. Same health as common grunt. Drones or miners can be quirk of high MMR version of this unit.
Grenadier: Armed with grenade laucher simillar to Loaths , this soldier can be very effective to smoke out from cover his enemies , keeping them moving and camping not viable option. Medium amount of damage and slow fire rate and cant shoot while moving. Also cant shoot if enemy close enough , making him very vulnerable in CQC. Medium amount of health.
Phantom: Elite unit what excels in CQC and have camouflage , making her very hard to spot. Using her camouflage she try to get close and finish off her target with machete. Very high CQC damage but dont have any ranged weapon. High movement speed. Same health as elite sniper.
Goliath: Mini boss what can appear at not boss stages. Big heavy armored unit what can be armed with different types of weapons: HMG , auto shotgun , electric rifle , grenade launcher. Acts simillar to Kuzzman boss. Cant run and grapple. Have huge amount of health and cant be headshoted but vulnerable from back. Can create shockwave in CQC , staggering and pushing enemies in its range and can use airstrike like Officer elite (have cooldown). Cant be grappled but can be punched.
Thank you for reading and please share your opinion!