A legit concern. The beauty about Devtal is actually the impact it has on the metagame, and not its actual power. I've used this to its full extent in two TPvP's, and I've yet to lose a single matchup.
Funny thing is, with more Steals it can actually become more powerful. Stolen Sancs keeps it alive until we get to the real kicker: Fractal Vamps. That's the killshot, and sometimes Devtal even skips Fractalling Devs in favour of it.
So, if anything, we modify our Devtals with more Steals and at least 3 Vamps. Or we just keep them as it is and make sure we use them at the right time.