I don't know where this not taking tail enders seriously stuff originated, with Miller there is always an excuse to explain a shortfall in his stats. With his batting, it's because he didn't take it seriously, his wpm, didn't take tail enders seriously. What is the excuse for his srtike rate? We can only judge players based on what they did, not what they were capable of.
As I was explained earlier, Miller initially in his career mainly bowled short bursts with the new ball, leaving Lindwall, Johnston ect to bear the heavier work load of the middle and old ball overs. As everyone knows it's harder to get wickets with the older ball and contrary to what is being implied you don't always only face tail enders when bolwing with the old ball. Everyone from the era acknowledges that not only was Lindwall the better bowler of the two but the best of the era and the best between Larwood and Lillee.
Not trying to tear down Miller who was a great All Rounder, and he does provide cover to play the two spinners, but why do we need two spinners when in general they have higher averages and strike rates that their faster contempories and their main value is the last innings looking for footmarks and being able to bowl long spells, one is sufficient to allow the fast bowlers to rotate at the other end. Miller's low wpm and high s/r doesn't lead me to believe that he didn't take tail enders seriously, but rather that he didn't bowl as much as he could of possibly, but more so, that he probably wasn't that effective after the initial bursts with the new ball as the ball got older and thus would be less effective bowling first change to Mcgrath and Lillee who would both be bowling fairly long opening spells.
Regarding the need for 5 specialists bowlers, the two best teams to play the game, used their primary four bolwers and part timers to fill what ever void was left, you want to have your four best bowlers bowling as much as possible, and full cover for your batting, because no matter how good your line up, collapses happens and you always want as much cover and specialists batsmen as possible, which is why I prefer batting All Rounders to pure or bowling All Rounders.
And no worries, I know everyone will disagree.