There is something seriously wrong with your computation. It takes around 16,500k xp to get from level 1 to level2. If each of your 4 members do a dungeon or two together every week and then do some dailies, they should each have no trouble hitting their weekly guild contribution cap. If you all hit your cap each week, you'd get to Level 2 in 3 or 4 weeks, not 3 or 4 years. I'm assuming here you're all level 80+. If on the other hand, your guild is made up of low levels, you might well be a at a virtual stand still until you all start getting up above level 70.
We all started at level 1. "Virtual" is an unnecessary adjective to "standstill". :)
But fair enough: "4 or 5 years" is probably a stretch, considering we will get to max level eventually and then start contributing more. "1 to 2 years" may be more accurate.