There's really no point me trying to convince you on this particular point; nothing I say will make any difference. If you think these players are the sort to make inroads in the Champions League, fair enough. I don't. Three of them had their best ever seasons for a club that was viewed as one of the biggest success stories of the year... and finished 8th.
Arsenal replaced RVP with Giroud but also bought Ozil, a world-class player. None of Liverpool's signing so far are Ozil-quality.
United, 'replacing' Ronaldo with Valencia, dropped a place on the table and five points, and were knocked out of the CL three stages earlier. This was despite the fact that we had a squad absolutely stacked with world class talent: Rooney, Scholes, Van der Saar, Giggs, Rio, Vidic, Evra, Tevez etc. Liverpool don't have that sort of quality cushion.
Spurs dropped a position in a season where United's implosion basically should have shifted everyone else up one. They were overtaken by Everton, who spent a minuscule fraction of their outlay that summer, and were roundly criticised for a terrible set of transfers by the pundits. And that's considering that Lamela was one of Europe's hot young things when they bought him, which none of Liverpool's signings really are.