Slivers have a difficulty level that updates with each kill. They all start at difficulty 1. Kill a sliver and the remainder update to difficulty 2. Kill 4 and the last one is at difficulty 5. Note that NW difficulty 1 is harder than SE difficulty 1, but NW difficulty 5 is way more difficult than SE difficulty 5. Therefore we do not want to assault NW at any higher difficulty levels.

The most important part of the run is to assault the slivers at the lowest difficulty possible.

After the initial biomass sequence, the closest sliver is kept at difficulty level 1 the entire time, by preventing rifts from respawning.

The first sliver assaulted is the west sliver, at difficulty 1. Then immediately afterwards, we assault NW, which is still at difficulty 1, about to update its defenders to difficulty 2, but we don’t give it the chance.

The third sliver at north is assaulted at difficulty 2, before it updates to difficulty 3. The fourth sliver is the one we forced into difficulty 1 since the start and has basically no defenders when assault begins. The final sliver is assaulted at the same time at difficulty 4, and it does not get the chance to update to difficulty 5.

Therefore, you do not fight a single sliver at the “proper” difficulty. This is the (unintended) consequence of having all objectives present from the start. More flexibility means more map abuse.