To address the original question: Their fight skill and strength isn't any lower than a normal orc - it's only their defense that is weaker.
I'm also considering orc trackers - but I would have them mounted on wargs. This will give them a fighting chance as it will increase their attack strength to 4 - give them charge bonuses - and allow them to move 5" and still shoot, and the warg is only 6pts - 2pts cheaper than a normal warg
bonus. The wargs will allow them to quickly move into shoot range - probably in just 1 turn.
Their only weakness is their defense - but at least on wargs half the hits will fall on the wargs who have higher defense.
Trackers are only 1pt less than normal orc bow - but on wargs they are 2pts less making them more appealing. Basically with trackers, you are getting mounted bow with better bow skill for 2pts less than normal warg-bow - so in 3 models you've bought yourself an extra tracker anyway.
I'm gonna give em a go - I'll letcha know how they get on.