One more strategy, just for the hell of it; Waiting. Britain was essentially diplomatically isolated at the start of the Boer war, and despite the strategic urgency many have cited giving cause to the war, the British did have other engagements at the time. The Fashoda incident had brought Britain and France to loggerheads, and there was an historic enmity with Russia in Afghanistan. The hostility the British experienced due to their invasion war in SA, as well as the infamous "Kruger Telegram" caused a diplomatic realignment just in time for ww1.
Also, I've read that had Britain not been at war in SA they very likely would have been invading Ethiopia, and possibly fighting France, due to their national railway project - Addis Ababa-Djibouti - being built by a French company, threatening French influence along Imperial lines of commerce and communication. Again, this fits with the "let Britain attack first" plan, because eventually the British would have acted in their traditional manner to enforce their prerogatives in SA, and the addition of time would only have worsened their position internationally.