Blood Bowl

Today I got Survival of the fittest, Cracked skull, Foul play and Veni, vidi, vici ! within one and a half hours.

The trick is that I imported my orc team from campaign (so this does only work with bashy teams (Chaos is another good team), as one might guess anyway).
I had 3 Black Orcs with Block and Mighty Blow, also 4 Blitzers with Tackle and Mighty Blow. They also had some other skills as well as my Linemen had Block and some random skills, but those are the important ones. You should try to get those while going for the campaign achievement.

Then create a goblin team in campaign and add 16 normal goblins. Make sure you don't hire an apothecary for this team. Then save and quit.

Start a one-off match, Blitz mode real-time on easy or medium, and edit the match rules first. Up the time limit to 8 minutes and deactivate all special rules (you don't want massive inductions for the other teams or the get the ref or riot kick-off events).
Import your orc team and the goblin opponents from your save games.

During the game, get yourself the ball, bring your ball carrier to the middle of the pitch and set all your players to the middle mode (not offensive/defensive), so that they come to the middle of the pitch. Most of the gobbos will attack your bulk of orcs and get smashed, all you have to do is watch your ball carrier and recapture the ball if your carrier falls.
If many of the goblins are KO'ed, you should score some TD's and set up again, so that the goblins can recover. You should also foul grounded goblins whenever possible for some extra KO's/casualties.
Also try not to lose the ball (neither score a TD) after the 4 minute time of the half is up, because time will run on for up to one minute if you keep the ball on your player (more time to smash those goblins).

These four achievements still require some luck, so repeat this one-off match procedure until you have them all.

I got this achievement and survival of the fittest in two games .

I was useing the Stock orcland raiders team against a lizard team of,16 skinks the little lizards .

I was averaging 6 knockouts in the first half in both my attempts first I went for kills second match went for knock outs .

I sent my players in a line with only the spot either side of the wingers open that way no one got a free run .

This game is not random so if you don't get a knockout or a kill in round one restart when ever someone scores save as long as you feel you have enough kills or knockouts by that time .

I let them score on the second last play which gave me one last turn to get 2 knockouts I had to restart a number of times but eventually I learned what move got me a KO and what didn't than I just did those two moves .

I also got 8 injures in these games I already had that achievement however .

If you start to kill or injury to many opponents I suggest reloading a save and not doing that move .

It might take you a few goes but this is by far the best way I found you don't need to make a team and as soon as you know what moves to do what you want and you should have no trouble unlocking this pain of an achievement .