No, Raiders should not be organized nor should they pause to reconsider attacking a well-defended location. On the contrary, Raiders are completely out of their mind on drugs. Just like Super Mutants, Raiders think that any sort of "avoidance" of danger is weakness. Stealth and/or tactics are not something that are in a Raider's dictionary. To Raiders, a larger, well-defended settlement says "look at all the loot here - come and get it and show everyone how tough you are taking it from the locals!"
Raiders in FO3 flee if they are seriously wounded in order to avoid dying, including screaming exactly that as they run away. People are asking for something that is already there in a logical way but it cannot be something that takes place before an attack or even as an attack is beginning, only when any specific Raider is seriously wounded and near death. Raiders are not thinking much of anything at all except "let's torture and mutilate everyone, take anything we want, and have lots of fun doing it." A Raider's response to one of their clan being killed is "svcks to be him/her" with no caring or compassion whatsoever. One less person to split the spoils with and feed, water, etc. The terminal entry in FO3's Springvale School sums up a Raider's "thinking" pretty well.
BOS? sure, they'll think, use tactics and strategy, etc. Synths? Of course, except if they have endless numbers being made (anologous to how insects do not care for the individual as long as the survival of the group is assured).
The last thing wanted is for Raiders to start thinking deeply about how to attack, tactics to use, strategic ambushes or retreats, etc. It would be totally unrealistic and out of character for them to do that type of thinking.