Warbands and Invasion Challenges - Help!

So I need that portal effect in my life and once Navali stops holding out on me I just need one of these challenges.

I have about 7 invaders or 9 warbands to go.

Do I need to run specific maps to spawn specific invaders?

Do I need to clear Beacon, Shipyard, Overgrown Ruin etc (sullying my pristine atlas) to spawn the warbands?

I've been chaining invasion and warbands leaguestones but I haven't seen a new boss of either type for maybe 50 - 100 maps.

At this rate I'll hit 1k maps before I complete one of the others.

Any help is appreciated, thanks!

I think there's a blue version of the warbands stone that says 'area has a commander'. Probably want to buy and spam those. Global #820 can help share if you're so inclined to leave it up and keep your eyes and ears open.

Ok, thanks mate

Dont waste currency on that leaguestone.

You need to farm sulphur wastes, overgrowth ruin, shipyard and one more map I forgot the name of, because the bosses are warbands there.

You get 2 wb leader on them and will cost you way less than the leaguestones.

Just make sure u run the correct map for your remaining leaders.

Yeah I feared that might be the case for the warbands, I think I might go for invasion instead.

I think the other map is Beacon. I don't want any of those maps unlocked and it costs about 15c per to unspec.

Cheers though.

Ok so I'm down to just 3 invasion bosses. Had reasonable luck running regular zones based on the monster type of the boss I was looking for.

But... I just can't seem to spawn or buy these last 3. It's not much fun running around merc docs and upper scepter for hours at level 94.

I'm actually thinking it might be quicker (and a lot less painful) to just run 300 more maps.

Invasion bosses NO ONE has bothered to answer my requests on what their spawn pattern is. It is tied to the zone, but I don't know which zones Wonderwalker will spawn. Have two mercenaries hunting.

Warbands is easy. 3 Brinerot, 3 Mutewind, 4 Redblade, 8 Renegade.

Equation I used to calculate how many maps you need to see all of them:

x*ln(x) + gamma*x + 0.5

So for 3 Leader Warbands you'll need to do 5.5 maps on average to see all 3 (Brinerot & Mutewind). Redblade you need 8 Beacon Maps. Renegade is 11 Overgrown Ruin due to two different bosses each time.

Both times this challenge has come up, in 2.4 and this patch, I got all 8 Chaos Warbands on the 11th and 10th maps, respectively.

Invasion bosses have no spawn pattern.

They are random, but also have a prefered zone/tileset.
I ran a couple of residence map to get one that ' thought would spawn there, and I received one of the others of his trio, then I proceeded to get the bosses that spawn in the vaal side areas in the sceptre of god, so I think this might be some pattern, but seriously invasion boss is one of the hardest challange I think, simply because even if it was completely random, you can do the standard deviation for the average attemps required, u need to run a shitton of maps regardless.