basically, but more likely you might do 1s x 5r, 2s x 4r, 1s x 3r x 100. Personally I would tend to stick to the intended weight. The answer to your other question is the session, remember the anology about CNS stress like a cup and wanting to fill but not overflow it? It ties to that.
here is an example I did the other week which may help explain things, especially the comment at the end.
Track
2 x 10m sled walkback rec
2 x 20m sled 90 sec rec
2 x 30m sled 2.25min rec
2 x 40m 3 min rec
2 x 50m 4 min rec
4 x 60m 5 min rec
Med Ball
Overhead x 10
Backwards x 10
1 Hop x 6
2 Hop x 4
3 Hop x 2
Plyos
5 x jump onto mat
10 x 1 step / 5 x 2 step 1 min rec
Weights
15 min block
Military Press @ 40 x 5, 5, 5, 4, 4, 3, 4, 4 = 34
Triple set
Chins @ BW x 4s x 10r
Glute bridge @ 90 x 4s x 10r
Dips @ BW x 4s x 10r
Abs
Stretch
EMS
20 mins achilles & quads
20 min ham & calf
20 min ITB
Rating
6
not quite 100% with a bit of a dry throat so flagged away squats rather than crash and burn by leaving them in.