And those in battles of tsunade we have seen she didnt show any sort of plan, she just kept puching around whereas kakashi has demonstrable battle experiene and has shown to be able to defeat stronger enemies than him with strategy , and he doesnt have to be the most powerful of the village to take the office, naruto and sasuke went along with his plans and listened to him even though he wasnt the most powerful out of them.
Again as hokage kakashi doesnt have to be in the front lines all the time, as hokage kakashi´s job will be to plan and assign the missions, so he´s got to be an excellent planner and strategist which he is already and has to know the leaf shinobi which he does, besides kakashi is well respected even by the most powerful shinobis within the leaf(like yamato) and other villages(raikage said he trusted kakashi), and as i seem to recall all five great nations are allied right now so they are in pretty good terms with each other, i dont think we have to worry about a kages feud.
And another thing kakashi is the captain of his own division, there are 5 divisions and there are 5 allied nations in the army, so if kakashi is the captain of one division out of five so it means he already has experience handling more or less the aproximate of people he would be handling as hokage.
Kakashi can and will be hokage i´m sure i believe obito´s words