This "line" is like the lines I've spoken about in other posts concerning spruce. Once planted in a line, look for deer - especially bucks - to utilize your "line" as a travel corridor for the security / cover the spruce provide. Once the spruce get to 6 ft. tall and beyond, I'd have several tree stands within easy shot distance - not kidding!! I've seen - and used (!) - such spruce lines in open hardwoods many times. Once the leaves drop - the spruce lines are the only cover left for deer seeking "safe" travel lanes.
Sandbur has spoken about HIS spruce and balsam as good deer travel spots. Bur noticed the same things I have once the leaves drop. Sandbur can comment on what he's noticed. I've added balsam fir at camp based on what Sandbur posted about his place.