They have beat alot of top club but if they only manage to get a draw only from all this top club then they will keep getting points and could become the champions. IMO their aim for european league only will get them alot of funds coming in and sponsors as well
But usually the team like this can't survive in top table due some key players get injured, so far Leicester didn't have any injured key player and i call it as a lucky.
They also have to escape the january transfer window without anyone coming in for massive bids for any key players. If a big clubs starts offering big money nobody is turning that down.