This pretty much sums up my view also. As soon as you see him come on you know we are going to play like rubbish in the hope something bounces off him. I know this worked occasionally last season (in high profile occasions) but plenty other times it led to nothing except a poor performance from the team.
You, like a lot of fans, are just thinking about last season and expecting the same to happen this season, when the reality is it won't. Last season was incredibly strange, with masses of players injured at various times, mostly in groups in the same positions ! either injuries or suspensions or both cost us dearly.
If the transfer talk is correct and at the very least we have GLC coming in, and lets say that either Eriksen stays or that Sessegnon also signs. Assuming everyone is fit because that is what you have to assume,then the striker is obviously Kane. regardless of system. If he is injured the striker is Son, and GLC/Eriksen/Lamela or Sessegnon take Sons position. If Kane and Son are injured, then Moura is the focal point. If Kane, Son and Moura are injured then a) Llorente plays and b) we are fucking unlucky. At a pinch we'd probably play Lamela there.
Point is, last season Llorente played in games where the whole team wasn't right, individually or as a unit. This season you have to start by assuming things won't be like that as obviously the problems were caused by the WC and then a smallish squad being stretched by masses of injuries.
I'm not saying Llorente is great, but in a Spurs side that is functioning properly, then he knows the system and players well, and should be able to play a role. Better that than spunking £10m on another cheapish backup player who comes in, clearly isn't good enough and never plays anyway.