George Herbert - Poetry

Yes, this series is back after a few weeks off.  As a reminder, in an effort to become more familiar and comfortable with poetry I'm (slowly) working my way through a book humbly titled 'The 100 Best Poems of All Time', which was put together by Leslie Pockell.  You can read through the previous posts by clicking the 'Poetry' link at the bottom of the post.
The next poem is completely unknown to me.  It's 'Jordan' by George Herbert, written early in the seventeenth century.

Who sayes that fictions onely and false hair
Become a verse? Is there in truth no beautie?
Is all good structure in a winding stair?
May no lines passe, except they do their dutie
     Not to a true, but painted chair?

Is it no verse, except enchanted groves
And sudden arbours shadow course-spunne lines?
Must purling streams refresh a lover's loves?
Must all be vail'd while he that reads divines,
     Catching the sense at two removes?

Shepherds are honest people; let them sing:
Riddle who list for me, and pull for Prime:
I envie no man's nightingale or spring;
Nor let them punish me with loss of rime
    Who plainly say, My God, My King.

Ok, so we have a poem about poetry.  Is Herbert condemning poems that are overly complex?  And poems that reach too quickly for certain imagery (enchanted groves, sudden arbors, nightingales and spring).  He seems to champion the simple and honest shepherds and their plain speech.  But he does this in a complex poem that is itself filled with imagery.
The book emphasizes that the title 'Jordan' refers to the Jordan river which separated the wilderness from the Promised Land.  Is that river then, a stand in for the separation between admiring pretty words and understanding the deeper meaning of a poem?  Or is that simply my lack of confidence speaking?
This is kind of an unsettling poem, and one I wish I could discuss in a group.