I really struggle to understand the meaning for くらい in this sentence:
The context is that these characters have just managed to infiltrate this futuristic fortified city. The protagonist says:
...これだけ発達した都市なら、俺たちが侵入したことくらいバレてるはずだ
Which I would translate very roughly and non-literally as:
… with a city that advanced, they have to know we are here/that we have broken in
But I genuinely can’t make sense of what nuance くらい conveys here. Is it just to soften 侵入する? Like “we have sort-of invaded”? Or is it more like “they should have figured out that we broke in or something”, as in he doesn’t know exactly what they would have detected, but they have to have found out that something was going on?