The point is to give each role a purpose.

I.e: Scouts that scout. Logi's that support (NOT attack), Assaulter's that make up the front lines, Heavies that take coordinated efforts to bring down, Dropships that survive long enough to give air support, Tanks that require coordinated efforts to be taken down, LAV's that actually SUPPORT infantry (lightning raids, rapid transportation, hit and run (not splatter and run))

Make the suits have some balance against each other.
For example;

The speed of a scout makes it effective against lone heavies, allowing them to outmanuver their slower foe, and their high DPS in CQC should make short work of him. However, an Assault at mid range would be very deadly to a scout if he were to try to attack. A scout should still be able to run away (thats what his speed is for right?), and to successfully kill a scout trying to run away, would require planning and probably more than one person. It would be the same as finding a criminal running in a building. You put men at the exits, and you box him in until he has nowhere left to run.

Medium Frames should be effective in all scenario's yet not a master in them. Their prime area is their versatility, being able to adapt their tactics to fit the need, always trying to get the enemy at a disadvantage, NOT themselves at an advantage. For example, engage scouts at mid-range (Scouts are only good in CQC). Attack heavies in groups (Give him more than one target to shoot at, he can only fire in one direction. Concentrated fire will kill him). They should move up to engage longer range opponents by moving from cover to cover, using their average speed and health to allow them to survive until the target is at a disadvantage.

Heavy Frames should be effective against medium suits at close-mid range with that HMG. That gun should shread through people not under cover, and force people to take cover. This allows the front-line to move forward. Since you are Aggro'ing at that point, the high eHP is important, allowing you to tank damage long enough for your front lines to move up. You stay still, they move up, you heal, rinse, repeat.

How the classes should be:

Make scouts great in 1v1's and CQC, but unable to survive sustained fire, making battle's against groups of enemies futile (thats the Assaulter's job). Give them WP for doing their job. Scanners should give WP on kills on detected enemies.

Make Logi's tough enough to SURVIVE behind the front lines. They should not be on the front lines (that's the Assaulter's job), they should give the Assault's a reason to fall back if need be. Mainly for health and ammo. They rez teammates after they push up, not sprinting to the front lines in a rambo revive (you have a 30 second timer for a reason)

Make Assaulter's versatile, and a "Jack of all Trades". They should be tough, yet flexible. Leave specialization to the other classes, you are there to be a Soldier. Proficient with your weapon of choice, and skilled at using it in that role. AR's should be an all around weapon, yet not outshine any other weapons specialization (Skilled in all, Master of None).

Make Heavies a force to be reckoned with. They should be the pushers, and the defenders. A heavy should be so tough, it should make the front line focus on him to take him down. They should help push the front line forward, by making the enemy fall back to cover. They should be able to shut down hallways, and mow down infantry and small vehicles with the HMG.

Dropships should be a form of air support and rapid transport. Think of the Transport chopper in BF3. Dang useful when used right. It could allow you to drop a whole squad in from the air, and even let your gunners clear the LZ, or help in an assault. Just like a chopper would.

Tanks need to shred though Armor, and Infantry at long-mid range. Close range is their weakness, but they should require coordinated efforts by AV to take down. They are the "big boys" for a reason. A lone AV should discourage attack but not kill. Two should wound a Tank FORCING it to move or be killed. Three AV should be the magical kill zone, (assuming standard meta level, ADV AV vs. ADV Tank, etc etc.)

If you fix these things, you WILL get your tactical shooter that most CPM's claim to want. I know this will not be instant, but I can wait, so long as I know that you are headed in this direction.

Feel free to lol, troll, agree, or debate as you see fit.
This is just my 0.02 ISK.