When looking at "small", do not forget thickness, or slimness through the slide as well as the grip section. Weight is not e real factor in my opinion, and I have owned and carried steel, aluninium and polymere. I realise we are not looking at carry options, and think fit in the hand and sight radius are more important for IPSC, IDPA, RSA or whatever legal shooting discipline you want to participate in.
The G26 is SHORT, but does loose some sensibility due to the longer barrel needed to keep it Canadian legal, but still handicapped by a short slide. The Sig 239 (Tactical, with the extended threaded barrel) is Heavier, but slimmer in grip and through the slide, and has a longer slide, giving it about the same or slightly better sight radius as the G26. Being 8 +1, is not bad when compared to the G26 10 +1 (when shooting IPSC). The HK P7 makes a lot of sense for useful slide length meeting Canadian legal, OK mag capacity in single stack models, and slim. The HK pistols are however very expensive, scarse and mags expensive and difficult to find compared to the G26 and Sig 239, but perhaps that was not part of the question. I have fired the G26 quite extensively and love the fit in my very large hand, but would love to fire the Sig 239, so no help there.
The Beretta (any "92", Vektor SP1, Taurus 92, etc.) is very wide / bulky through the slide due to the "wings" on the locking mechanism, and in my mind will never qualify as compact.