The idea that it is better to plant a variety of plants instead of a single plant type when creating a border/hedge/screen is tossed about all the time (frequently here) and the justification is fear of disease. Personally, I think the actual instance of this happening is so low that it is negligible and a non-issue. I believe that the real motivation behind it is plant-lover's desire (or obsession) for variety and since people want to hear what they want to hear, this seems like a bonafide clinical justification. Nevertheless, there is good reason not to plant a variety of plants when creating a border, hedge or screen: good, clean looks. How many people plant different types of lawn grass if variety is so important in a single yard? Take your pick and do as you please.

I would like to toss out another way to create a screen that is cheap and easy ... cheaper and easier that constructing trellises of lattice. Here are two ways, of which the first (chain and twine) is the method I generally prefer, as it is cheapest and easiest. One could make single sections only a few feet long, or extended runs that cover tens of feet. (Naturally, in a run of trellis like this, one must brace corner and end posts just as they would with a fence.)

In the picture below it is covered with annual vines (moonflower vine) so the coverage is quick ... about 6 weeks from planting seed.

Obviously, with annuals, there's not going to be any screening effect once the plant dies for the winter. I use annuals for quick coverage and also plant a perennial vine for permanent coverage. Even a deciduous perennial vine can create some degree of screening when it has no leaves. Each vine has its own personality so one needs to pick accordingly.

In most cases, where the vine meets grass lawn, it is the lawn mower which does the trimming. If such a trellis were planted a few inches inside the existing chain link fence, vines would also "eat" the fence, covering it completely.

Well, I'm one who prefers a mixed shrub border. I'd plant a mix of viburnums, conifers, maybe a Magnolia stellata or two, ninebarks, rhododendrons (if deer are not a problem). Lots of year round interest, easy care. You'd have to expect it to be some 12-15 feet wide. (Less lawn to mow is always a plus as far as I'm concerned.)