Nope, you don't need plecos IMO.
I didn't have any plecos in my tank for about 2 years from the time that Damien died & I got AL, but mainly that's because they are hard to get in my area, so it took that long to even get my hands on one when some stock arrived.
Even if you do get an algae bloom, just cutting the lights for a couple of days will keep it in check; I don't recommend using any of those algae destroyer chemicals as they can be toxic to fish, but to each their own I suppose.