It's not the big standard ones you need to be scared of, it's the minelaying ones. Discover AROs then generate a template that takes a chunk out of your backline
On the flipside, Camo markers and minelayers will at least make the Speculo work really hard to get its kill. Camo Markers can also deny the minelayer Speculo a good place to put its mine down.
Speaking as a long time shasvastii player who enjoys the new minelayer profile, nothing upsets me more than camo markers planted near juicy fireteam targets. Since the minelayer skill doesn't allow you to deploy mines anywhere where camo markers are in the trigger area. Several savvy opponents have been using naga minelayers to prevent me deploying my mine where it can hit the stuff I want it to hit.
A speculos purpose is to rattle you, don’t let yourself be rattled, kill it, move on and concentrate on the objectives. Remember, even lowly line infantry can cause havoc in Infinity, the speculo just happens to save some orders to get close to you.