A man of God shouldn't be focused with these activities but instead does the work of an evangelist and ministries [2 Timothy 4:5]. And us, being gamblers, we know that others predictions could help our bets but we shouldn't rely on them at most times. Always take care of your money and so as your bets. No one need to blame for this but ourselves if we're the one who placed the bets but we did listened to someone else to bet that money. If we gamble, we have to make sure that there is no other person that's involved on it but us.
I agree with you, a man of God should focus on ministry work than match prediction hence there is connection between gambling and religion. Infact religious people frawn dearly at gamblers. So making pronouncement about the club to win is indirectly associating with the world and may ruin his ministry. The problem is that most of this men are not real men of God but they hide under the shadow of Christianity and tarnish the image of God. As far as I know God is not an author of confusion or God is not a lier so making a false declaration in the name of God is blasphemy. So my opinion is that people should avoid prediction from this men that forced themselves to be pastors and do what pleases you.
You've said it already, many of them are false prophets and that's why they're engaged into it. But it's up for the people to decide, I am just saying that something like this shouldn't be for the people who are dedicated to the works of spreading the Words of God. They can have their own share of fun but it shouldn't be aligned to these matters when they know that it's going to put stain to their chosen calling. And we as normal human beings living with our lives, are easily criticizing them because that's how it should be, right?