I completely agree. The issue is the lack of depth and experience in the squad, which means Arteta really doesn't have great tools to tinker much. He has done very well to have us playing a distinct, high intensity and attractive style of football, and has brought in the right players to suit that style. We have come a long way from end of Wenger era to Emery days when we were disjointed with no clear playing style, pretty much just relying on our strikers to carry us (when Auba and Laca were good). We now have a very clear stye and when we go into the transfer market, we have a plan about the profile of players we're looking for. Part of how he's developed us is by keeping consistency and not changing his team unless necessary. He knows his best XI and sticks to it.
The downside is that we have become very rigid and have no plan B, but I think that will improve as the squad gets deeper and more experienced. The lack of tactical flexibility and ability to adapt IMO is mostly due to the squad's inexperience. The commentator said in the game that if Arsenal win the title, we'll be the only team to have done so with the youngest squad in the league. Goes to show that we've probably over-achieved, as you really need more experience to win titles.