Woodcarver is the nemesis and polar opposite of Flenser. As is pointed out in the book, the names are characteristic of the attitudes harboured by each, and consequently the behaviour you can expect from each.

However, there are similarities between the two great leaders. Woodcarver, like Flenser, believes that a (sentient) pack's traits can improved by the selective inclusion of (non sentient) individuals possessing particular traits. Woodcarver itself is an example of genetic engineering - in it's case, selective breeding. Woodcarver inbred it's component animals to emphasise the most admirable traits, and as a result is the wisest person inhabiting that planet.

Scriber takes a new member into himself on the battlefield, but not without concern: Scriber initially is composed of the smallest number of members needed to retain sentience. When a member is killed on the battlefiled, Scriber is joined by a single remnant of one of Flenser's soldiers, the first single animal the mentally flailing Scriber encounters. The violence and lack of intelligence of the soldier "dog" is tempered by the stability and commonsense of the remaining animals comprising Scriber. This combination works out, but I feel it is inaccurate to say that Scriber did this with little concern. More to the point, I contest that Vernor Vinge's book "A Fire Upon the Deep" contains a criticism of genetic engineering, but rather an examination thereof.