UPDATE: seeing there is no answers, yet the views increase, i concluded that this is not a dumb question, which then everybody could answer easily (though at first i assumed everybody already know about it), if that is the case i want to ask, which section is appropriate to put this post? (is this post contains spoiler?)
EDIT: Removed unnecessary details from question (sorrry though, i have a nasty habit of getting too much into detail, and most often says the most obvious, when doing so). Edited the question to be more "concise". Added necessary information.
If you play alchemist, there is usually a talent on your hotbar (interact with your golem), there is several options, one of them is " i want to change your tactics", which could also be accessed by crtl+F2, or could also be accessed by right clicking to your golem's portrait above the screen.
After you do that, there will be another options, one of them is "set behavior" option. If you choose that, it will give you 5 option, namely: Melee, Ranged, Tank, Standby, Default.
The Question:
1. What it actually do? I can't seem find the difference after changing them. Is there a different key behavior for each option? if there are, please explain,
2. Or Is it even actually useful? I mean, if the golem behaves the more or less the same regardless what i choose, i could say the option is useless, is that is the case? ( I believe it had some usefulness, because there is no merit in adding that option, if that is actually useless, and if that's the case, it should be removed)
The least Expected answer, (thanks for answering though

Forgive me if my post is disturbing or lacking in any aspect, if that's the case, you can PM me to remove it.
Thanks

Flurryboots