I'm reading - there is comma between the two names "Zuo Ci, Gan Ji" - obviously you are right and this comma means "AND" :)
Which leads to another question - where are you reading this? Is there a guide about fate, or you speak on your own experience :) ?
I have a general note on this stats in Equipment - not always these are figures are exact, but more as a guide line.
For example - I have red spear, which increase:
(add 4.67 x STR to phys. Attack and add 1.0 x STR to str.Attack )
and in the above figures (DaQiao example) it's:
Spear + STR
(add 3.42 x STR to phys. Attack and add 0.4 x STR to str.Attack )
Another example is a purple spear of mine:
(add 3.89 x STR to phys. Attack and add 0.76 x STR to str.Attack )
But I'm not sure if this is changing with the equipment level, or this is coded from the beginning. I will add more notes later.
If someone has more observations - let's add them :)
It's a question of luck :)
Each 5 stars equipment starts with 4 increments - attack, defence, Evasion, Rage, Max troops, Critical hit and so on. They become visible after first upgrade.
So you have to try. On every 3 upgrades one of the increments rises, but there is also possibility a new one to appear (I'm not sure for the last...)
Best equipment is Red with 5 stars, followed by yellow, purple, blue and worst - green.
May be 5 stars yellow is better than 1 star red, but it depends on your choice and the increments - this up to you.