"knows nothing about this stuff" - There is no silver bullet for this.
Engine is just small part. You still need to make art, music, logic, UI, etc.
Engine helps to you to put that all together, here Construct can do it faster. With some other engine you could do it same fast, but it takes longer to mastered them. Ofc after you have mastered them, they can offer you more/less depending which you use.
"how many hours it'd take to prototype/make"
It depends how long it takes for you to make them. Like some art, some model in blender, animate something for you game. Make or modifie and play around with sounds? Design game world?
Does no matter what you choose, it all takes very very long time to do. And your "minimal spatial tactics on multiplayer" game consumes your soul at the end.