i think it's because the sailor needs to be within that span of levels of the ships level

Sometime ago SDE introduce this change, that allow to load sailor up 14 levels down in CV´s.

Sorry "that makes no sense"

That sailor is 30 levels under

And that one have 34 levels above

it's me or that ship only can enlist sailors betwwen 46 and 74 level

But the rule should not allow put the 30 level sailor, but it is

The rule only applies to pilots.

IF your CV (ship) is higher level than pilots (14+ lvls) - your crew will be automaticly thrown off after u'll leave harbour and they will not be usablable in the battle and after it will recieve 0 XP.

if pilots are higher level  then CV - it's no restriction

easy sayed for example:
CV3(lvl 75~) with 60 lvl pilots will not be usable
CV1 lvl 60~ with 120 lvl pilots will run without problem

Nobody here seems to have read properly OP's post.

Apparently he can very well put onboard pilots lower than 14 levels below CV level - if they are still classed rookies.

The rule of "no lower than 14 levels below" seems to apply only to fighters and bombers, not to scouts ("rookies").

It mainly to stop people form doing something unexpected . i.e PCV or CV6 use local to massacre bomber, fighter at close range, which forces higher level CV to be compotent to deploy fighter far enough to stop bomber rather than be unexpected. 

I personally think local should be allow on PCV and CV6 to allow dynamic game play. The game need to encourage people to think outside the box rather than this is the only way it going to be.