Lucky attack rate

After hitting lvl 20 recently the game has become much more boring with no lvling goal. I've mixed up my army type and am now thinking about changing stats.
In the past I've stuck with equal attack and defence with nothing in fortune.
I'm considering switching to max fortune with the rest in defence and would like to hear other views/experiences on a couple things.
As my enhances are almost maxed, enhance stones will be of little concern to me so my main focus would be the lucky double attacks.

With max fortune (either 100+10 or 100+20, I'm not too bothered which) what is the average rate of lucky attacks I could expect to get?

Also would the combo described above be advantageous for a cav/arch or inf/arch army?

I'm sorry I can't give a concrete rate, but I usually get 2 out of 5 attacks as doubles, and an occasional lucky triple.
I highly suggest it over attack for armies based on ranged combat, especially cats, but with inf and cav, I prefer attack for consistent results.
There will be good debate on the subject, but I hope you decide to try and see for yourself, regardless. Fortune has a habit of coming through when needed most, as evidenced by that 800k hit in another thread.