The Invader ATV Squad was created using the Attack Bike Squad as a base, and applying the Primaris modifications seen on other datasheets, especially the Tactical Squad => Intercessor Squad comparisons.

The base profile stays mostly the same, except for doubling the Wounds characteristic, following the Tactical => Intercessor pattern. Unlike the Outrider Squad, this actually matches 9e as well, since the Invader has double the wounds of an attack bike in 9e, while an Outrider only has 4 wounds, compared to 3 for the Space Marine Biker.

The Close Combat Weapons profile stays the same, except for doubling the number of attacks, following the Tactical => Intercessor pattern.

Light vs Heavy

We decided the Invader ATV Squad should be Light. Comparing the model to Land Speeders, which are heavy, indicates that the ATV is squarely on the fuzzy line between Light and Heavy - their stat lines are VERY similar. In the end, we decided to keep it Light for two reasons:

1. The Invader ATV has the Biker keyword in 9e, not Vehicle - Land Speeders have the Vehicle keyword.
2. Crossing over the Light/Heavy boundary completely changes the math for wounds and other stats - Land Speeders only have 1 wound per model, for instance. It was relatively simple to apply the Primaris rules to the Attack Bike profiles. Having to find a different heavy model to compare to seemed like hard work, and we are lazy.

Power Level

Invaders are 2x the PL of Attack Bikes in 9e, so we could double it for Apocalypse, too, making it 8 PL per model. This is almost definitely wrong, especially since Land Speeders are also 4 PL. We decided to make it 6 PL per model, for no real logical reason other than 8 seemed too high. shrug.