how is it a card discussion if you don't bring up any points to argue? and of course solemn warning beats glads, its a staple card that runs in every deck while glads are limited.
Solemn warning only negates the tag effects, so it destroys the monster that goes back to the deck, which usually is the bait glad to get the tags started for contact fusions. In most situations I let them tag if I know they are going for gyzarus or whoever that thing is that needs laquari because those are much bigger threats then their tagged out monster.