There are several ways to look at it, I like to look at the accumulation of high "intensity" stressors to the body.
For example, I'd prefer to see this cycle:
Day 1: Strength + Speed
Day 2: Off
Rather than this cycle:
Day 1: Strength
Day 2: Speed
Speed being genuine work on speed, not necessarily conditioning. The speed work is an iffy thing for an American rugger. The cost/benefit ratio is often not there, and he's almost always better off working on being much more highly conditioned that he is.
I'd rather see the first because you aren't spreading out your higher intensity (and I'm talking about impact to the body and to the CNS). Metabolic conditioning is almost always has a higher impact on the body but a medium to low impact on the CNS. Conditioning running can be set up AFTER weight work in the cycle (to minimized the deleterious effects upon the strength work)
American Rugby is almost always set up like this:
The problem arises when your coach wants to perform conditioning during practice.
So, the first question is "Am I getting enough conditioning from practice to play?" The answer is probably not until the season begins.
The second question is "Am I getting the right kind of conditioning from my coach?" Again...in the US, probably not, though it seems to be catching up to speed.
Ah, you see, already, my thoughts are more organized than they were yesterday.