I don't agree with this. You can handle openings by using a pre-computed book.
If you think about it, this is actually how humans handle openings. There is an opening theory, to which huge amount of analysis(pre-computation) was done. Even professionals don't do impromptu opening analysis over the board.
On the other hand, in my opinion computer tactics are nowhere close to professional level. Not even close.
Openings can't be handled by a pre-computed book. What we humans call the opening can be 40 moves, and professional games often feature unique moves within the first 10-20 moves.
The situation with regard to the opening is quite different from chess.
Of the corner opening patterns alone (called joseki), there are 10000s of them, and it's very common to use novel ones. Many joseki, like the well known 4-4/3-3 invasion, can range from great plays to disasters depending on board position. And there are four corners.
The approach of trying to repeat the human process for pattern recognition is probably the main reason why bots were so weak until it was decided by a few computer scientists that Go should also be battled with brute force.
In one of the Zen vs Takemiya(?) or other professional games, the bot manages to kill a group by the professional with razor-sharp precision, including several tesujis. They excel at local tactical situations, and in terms of killing groups in a big board, they are excellent at poaching eyes.
If you think about it, this is actually how humans handle openings. There is an opening theory, to which huge amount of analysis(pre-computation) was done. Even professionals don't do impromptu opening analysis over the board.
On the other hand, in my opinion computer tactics are nowhere close to professional level. Not even close.