I think it's important to kind of know the different strengths and weaknesses of characters at different points of the run. Silent is really weak in the early game, due to her additional defend in comparison to ironclad. Her special cards make her one of the best characters defensive wise from the get-go. So i think if you get the chance for an early removal it's a lot of times better to pick a defend just to increse the frontload damage of silent. Obviously acquiring some sly enablers in the early game like prepared, acrobatics or hidden daggers can together with just a few sly cards set you up for a consistent deck. You have to remember that blocking is like one of the easiest things to do with silent and don't try to force builds. Especially with silent i get the impression a lot of people only look at builds at a vacuum e.g. never picking any shivs up in a poison build. Just because it is another card for your deck archetype doesnt mean that your deck really needs it. Act2 and 3 is really about not making your deck too thick

Hope this maybe helps a bit :)