I tend to split my tiers up into platforms. This provides me with the ability to be more flexible with how many links are directed towards which platform.
To take this level of control one step further how about a link indexing check function? You could then run your links through the indexer and then by way of a check box (only build links to non indexed links) focus upon all links within your projects which are yet to be indexed in G.
In the current climate its all about getting the links you build noticed - if we can focus in on specific links which are not, it will really help give more power to our campaigns.