Horde Ememies & Boss Issues(possible spoilers I will descuss emegies in game)

[Stagnet]

I used the search option didnt find anyone with this problem yet but I have played all 50 waves of Horde and have not seen any variations of the Enemies I have only seen drones, lambent drones, lambent wretchs, Tickers, Boomers, Grinders, Drudges, and Therons. The only Boss I have seen was the Gunkers AKA Lambent Boomers I had then on every 10th wave. What wrong do ememies change with Difficulty? Does it change with number of Players? Does it matter the map? There were 2 of use and we beat it on normal mode and beat it on overpass.
In my stats it shows many ememies I have not faced examples are any locast that are savage drones Kantas Therons. I have not seen any Digger boomers or butchers which sucks cause I want to use the cleaver. I have not seen any variations of the bosses corpsers, reavers, beserkers, or the Burmak.

Please this really sucks and it is killing the fun seing the same ememies all the time when there are so many more that are in the game.

[TroyMcClure]

It is random, map and difficulty has nothing to do with it... All of the Savage characters, Digger Boomers, Butchers, Savage corpsers etc, are in one set of enemies. The reavers, serapedes and Armored Kantus are in another..

The game selects one set of enemies for every 10 waves. Just keep playing and you will see them.