I don't think BigAnt can win here. If they make bowling anymore difficult then people will say that bowling is too hard. I find bowling quite difficult in career mode and find myself bowling overs and overs without getting 5-6 wickets. I would be lucky to get 1 wicket per innings and I am not bowling badly at all as the same type of bowling in Competition Mode gets me 5-6 wickets in T20I's and about 8 wickets in ODI on PRO difficulty. I think the number of wickets is okay for me just the number of runs they get is the problem.
I think the problem is that the AI do not bat to the situation. They don't seem to realize at times that there's only a few overs left and that they have more than 5+ wickets in hand so they should be going after it. I have had the AI cart me around the park with 100 from 10 overs but they somehow slow down and score 3/140 in the 20 overs. Sometimes they are chasing 150 runs and they end up with 3/129 after 20 overs. They don't seem to appreciate sometimes I bring a part timer or a "pie thrower" and only score 3-4 runs off the over - you could bring on a batsman with no bowling skills and bowl a tight over. In ODI's they don't appreciate that if they have lost a few quick wickets that they can form a partnership as there is plenty of overs left and wait for the final 10 overs to have an almighty slog to get to a respectable total.