Adware Medic actually removes certain adware on an ad-hoc basis, while Safari extension ScamZapper blocks certain browser popups. CIRCL’s ALOD runs in the background and lets you know if files are about to be installed in locations previous malware has installed components, and leaves you the choice to proceed with that or not. Only the latter two may run simultaneously with normal use. So these utilities do different things and can coexist, at least in principle.
The questions that remain include those about how well these apps play with others. Do they slow down your Mac or web browsing or otherwise negatively affect your computing, and if so, is that interference worth it to you? That’s likely both hardware and OS version dependent, and as such difficult to answer generically. For instance, and FWIW, I haven’t yet noticed anything untoward with ScamZapper and ALOD, or otherwise seen reason to uninstall them, running Yosemite on a retina iMac.
