The game lacks its own internal logic in various ways. The OP regarding time and space is just one aspect and points such as Gray Ghost's above abound. Too much of the game consists of things that are there for the sake of being there or stage-managed to happened at precisely that moment.
Comparisons with other games are largely irrelevant and nearly always degenerate into "I preferred game A" and "but I preferred game B".
Example of the first type: Entering the Underdark from the Zhent hideout. At the bottom of the knotted roots you immediately step into minefield. Who placed the mines? The Zhent? Common-sense suggests they would place the mines at the top of the roots. Some denizens of the Underdark? Who? The first creatures you meet (within a few metres) are the minotaurs. The bulette also works this area.
Example of the second type: Last Light inn. Why does Marcus attack not only just as you are talking to Isobel but after you have just received the blessing thing? Why hadn't he abducted her 5 minutes before you arrived or 5 minutes after you left.
A wrong outcome here (not a wrong choice) can result in the deaths of 10 or so(?) named NPCs who featured in Act 1 as well cutting off some side quests etc.
A side note. Given that there are three(?) entrances to the Underdark then the scale used in the Underdark should match the scale used in the upper world which should match the scale used in the Zhent hideout which should match the scale used in the Whispering Depths ((?)the spider place).
