Real Madrid team is not in a state to flog Arsenal now as you are thinking because they only have vast Champions League experience more than Arsenal because they are the team with highest Champions League trophy in the world and Arsenal did not have even one, but that should not be used to judge Arsenal case now because Arsenal team is more reliable than Real Madrid team that was struggling to win matches in Laliga just because some players were injured.
These two teams are in different groups in the Champions League this season and I don't think we will link the performance of the two teams to compare what is happening at the moment. This means that Arsenal will focus all their energy on being able to win the next match against Sevilla where in the previous match arsenal lost points when they faced Lens. So arsenal opportunity to return to winning ways when they face Sevilla. I think Arteta must improve Arsenal performance in the Champions League this season to improve their ranking in the standings table.
Well, as you said, Real madrid is a quite experienced team in the Champions League and that is true. Even Real Madrid are kings in the Champions League because they have won the UCL trophy 14 times. And this season the storm of injuries that has haunted the Real Madrid team seems not to have had quite a bad impact on them in the Champions League because Real madrid is currently the leader of the standings in group C.