So, I'm finally ready to get into my first full playthrough of D:OS and I want to play on Tactician difficulty.

How hard is this mode actually? I read a lot online about guides for tactician and honor mode, power builds etc. which might lead one to believe that you MUST abide by certain character development guidelines or you will get stuck because of overwhelming difficulty at some point.

Is that really the case? Or is it safe to "just play the game"?
I mean, it is obvious that it would be a bad idea to drop all points into lockpicking, pickpocketing and other non-combat related skills but can you mess up really bad in a gamestopping way even if you focus on combat builds for your two source hunters?
Do you really need these very specific builds ("Dual Wielding Grenade Wizard") from the online guides to beat the game on tactician difficulty?

Thanks in advance for any input on the matter described above smile .