Head smashing was also present enough in episode 5x09 to give us reason to believe Negan is around. When Noah found his old house, he found his mother with her head smashed in the living room. Very similar to what Negan did to Glenn.
A trade-off is a situation where you make a compromise between two things, or where you exchange all or part of one thing for another. ...the trade-off between inflation and unemployment. American English: trade-off
Trade, in general connotation, means the purchase and sales of commodities. In International Trade, purchase and sale are replaced by imports and exports. Balance of Trade is simply the difference between the value of exports and value of imports. Thus, the Balance of Trade denotes the differences of imports and exports of a merchandise of a country during the course of year. It indicates the value of exports and imports of the country in question.