nah, the way SR5 works now, you knida need a decker in your group. he should be picking up the slack to defend important gear like RCC's + drone nets. A rigger with some hacking skills isnt a bad call, but decks arent cheap and neither are good control rigs, RCC's and a modded drone fleet.
you could feasbily build a defensively minded rigger who can deck, maybe codeslinger: data spike +2, cybercombat 4 (personas +2) and a good LOG attribute with a basic deck tailored for defense.
tbh though, the liegelord RCC with the extra cyberprogram support of shell + encryption in full matrix defense is probably fine as-is. stand next to some smart jammers or point a directional jammer at the decker and he's gonna be at quite a few
-ve modifiers on his matrix actions. you can always keep feeding him an agent program to cybercombat to buy you some time, but your best defense against deckers is your own decker.
failing that, ramp up the noise with jammers and go full defense.
lastly, you could tool for cybercombat yourself and go kick his ass, but i wouldnt recommend that as it might go horribly horribly wrong.