The stats in HP, Def and SpD will look like this, without factoring in natures;
Snover - 262 HP, 298 Def, 327 SpD (Give or take one, my rounding may be incorrect) with eviolite
Abomasnow - 322 HP, 249 Def, 269 SpD
Even though Snover's defensive stats will rise above Abomasnow (not by too much), Abomasnow's higher HP makes up for it, and it's access to leftovers. Also Abomasnow's higher speed allows it to outspeed some Pokemon Snover would not be able to, and that can mean that Abomasnow can potentially dodge an attack, which is always great.