Not a problem with this for me. In the FMC RM one season game, not finished, Bale did get an injury, three weeks and that was all.
In my main save in full, a few important players have started to pick injuries towards the end of the season. 3-4 weeks at most, save for one picking a 4 months injury.
It is broken because of that?. No, it is as it should. Really, what players will your opposition focus their hard tackling on? In your better players that are threats to them.
And yes, tactics and training do and HAVE TO have influence on how many injuries players have. A hard tackling use across the board with heavy or very heavy training workloads will necessarily make much easier to get injured players than easy tackling and light workloads.
Does it mean there can't be ever a bug with injuries? No, there may be bugs with it, that I haven't experienced, as if I look at the real injury table for the leagues I play I find out it's very alike to the injury table in my game. Moreso: the real injury table has more and worse injuries than the one in game.
Then, there are so many whiners who want to be free of injuries when playing very heavy workloads and high tackling across the board, also against hard tackling teams that you can't pretend people to take seriously a complain on injuries that don't include extensive information on the shape of at least the save game uploaded to their FTP server for review.
The problem I have with injuries, that I reported in the bug forums, is that when your player get a relevant knock (green cross), the match feed doesn't notify you of that most of the times, and when it does, it is much later; so if you're not attentive you may unwittingly have a player with a fledging injury be straining it further by playing with it for a long time, turning what could have been a few days injury should you have subbed him immediately into a serious long term injury because you didn't realize he had the injury.