I will share my own personal finding on this. Love is crucial for harvest, but wisdom can be attained and you can program / may have pre-incarnative programmed lessons for it.
The Ra material states that open love is 'the salvation of third density' (42.6) but it can create a mismatch in the balance of an entity.
My own past life regression has me down as a 4th density wanderer, seeking to gain more understanding and to lay the groundwork for fifth density.
My understanding is wisdom is not required for harvest from third density, but almost certainly can be gained and I would recommend it. My mental capacity for logic is very high and it seems to have placed me in a position to learn key lessons of wisdom, especially discernment and not sending out extreme amounts of love where it is not wanted/needed. Endlessly showering love on people can drive them mad if they are ill-prepared, as I have learned the hard way throughout my incarnation so far, thus wisdom where expression of love is concerned has been a lesson of mine.
I will note that many fourth-density beings I have channeled/worked with are often less 'wise' when planning sessions and/or being able to detect when a session should end, as much as a fifth/sixth-density entity of which I work with a few, and the boundaries for giving information re. free will seems to be lower at fourth, as opposed to fifth density or higher, the lack of wisdom can become very obvious in my opinion. I also see lack of wisdom in many spiritual practitioners; who do not know when to ground, and can be very unbalanced, completely open in love and compassion, but end up in a state of what I call 'spiritual overload' and I find their mental functions degrade to a stage where they can barely function in the world, unless the balance is restored through energy work, though some of this may be a byproduct of the wanderer incarnating to a lower density.
Wisdom I think is crucial when you want to do the likes of channeling or spiritual work of high service to others purity due to the effect of drawing the opposite polarity to you. It is not for us to be fully wise or understand at this density, for that is not possible I don't think due to the veil. But many of us have programmed lessons to give us opportunities to be wiser. Take the path of Carla as an example of that.
A new fourth-density entity I met 'Dazna' on a spiritual travel (see this link on my blog:
http://www.loveseekers.org/category/spiritguides/ ) thought the idea of Wisdom was absurd, fifth density entities were spoken as of the 'wise ones', just as many here find open love absurd, many early fourth-density entities see wisdom as absurd, though our social memory complex seems to have an understanding of the importance of wisdom and have a strong seeking towards fifth density.
My aunt and mother were of fifth density, and many of their life lessons appear to have wisdom as the basis, my aunt seems to be trying to balance a heart with wisdom, my mother seemed to have a very good balance in this regard, and after completing her planned missions promptly left this incarnation and this third-density cycle based on my communications with her spirit and from my own guidance team, as she, my aunt and other family members are part of the teach/learning relationships in our soul group. My mother was very loving/kind to anyone, but was also very wise and had an intuition that served her very well.
Remember the third density experience is extremely powerful, vivid, intense and can thus be used to learn lessons that would take much, much longer to learn at the higher densities, wisdom is easily one of those potential lessons, as well as completely open love in my opinion. Neither more important than the other, though if you have learned neither, learning the lessons of open love would take priority over trying to be wise if you were trying to polarize as fourth-density positive.