Here's an idea I had while musing on psychology in Warhammer. If you want some of the feel of a 40K campaign, but don't have the time, ideas or consensus it can take to set one up, ponder this.
                                                                                                                              

At the end of each game, note the degree of damage done to each unit which took part.

If the unit was reduced to half strength or destroyed, casualties will be replaced with reserves or trainees: the unit is classed as rookie in the next game in which it is taken.

Any unit not reduced to half strength or destroyed is classed as hardened in later games, until it would be classed as rookie, at which point it reverts to its normal status.

Rookie units roll one extra die for each leadership test, discarding the single best result; hardened units roll one extra, discarding the single worst.* Where the unit is a vehicle, a rookie crew fires one weapon less than usual, while a hardened crew can fire one more.
                                                                                                                              

The variety of sixth edition means the wider strategic aspects can be assumed in the particular combination of factors in any given game. This just adds a little consequence.

It could go on until a climactic battle is arranged, agreed maybe 1D6 games in advance.

* Optional rules: Naïveté - if a rookie unit rolls a double or triple on the dice for any leadership test, the next casualty suffered fights on with a single wound; Shell shock - if a hardened unit rolls a double or triple on the dice for any leadership test, one model - chosen by an opposing player - is unwell and immediately lost.
Here's an idea I had while musing on psychology in Warhammer. If you want some of the feel of a 40K campaign, but don't have the time, ideas or consensus it can take to set one up, ponder this.
                                                                                                                              

At the end of each game, note the degree of damage done to each unit which took part.

If the unit was reduced to half strength or destroyed, casualties will be replaced with reserves or trainees: the unit is classed as rookie in the next game in which it is taken.

Any unit not reduced to half strength or destroyed is classed as hardened in later games, until it would be classed as rookie, at which point it reverts to its normal status.

Rookie units roll one extra die for each leadership test, discarding the single best result; hardened units roll one extra, discarding the single worst.* Where the unit is a vehicle, a rookie crew fires one weapon less than usual, while a hardened crew can fire one more.
                                                                                                                              

The variety of sixth edition means the wider strategic aspects can be assumed in the particular combination of factors in any given game. This just adds a little consequence.

It could go on until a climactic battle is arranged, agreed maybe 1D6 games in advance.

* Optional rules: Naïveté - if a rookie unit rolls a double or triple on the dice for any leadership test, the next casualty suffered fights on with a single wound; Shell shock - if a hardened unit rolls a double or triple on the dice for any leadership test, one model - chosen by an opposing player - is unwell and immediately lost.