It's funny because most of managers on this forum play in lower division than You ;-)
But more important is that most of us play in completly different game than You, because strategical and economical situation in Your country are different and therefore Your steps should be different.
You have only 25 opponents in Your country so You can check all of them to recognize who is dangerous for You (You should compare their squad, statistics, arena size, how offten they are logged in BB, transfer activity, etc). I think real number of strong opponents is lower than 25, because I see few teams in Your league aren't logged for few weeks.
If there is no stronger team than Your then You should try to win cup or championships as soon as possible ;-)
If there are few stronger clubs then You should invest all Your cash to increase Your arena. It's more important than traning because in Your situations revenues from training are very lower than incomes from tickets.
And tactic isn't so important because every week You can earn cash to simply buy new player twice better than old. So every week You can have stronger team and use different tactic (depending on new players).