In a perfect world Metrinka's suggestions make sense, but we're talking about real world field welding conditions that are totally different than applying the same sort of thinking one would use in shop work which includes for the most part consistent and optimal joint openings, etc... Why is this different working on a tower? Because of the inconsistencies that will be found in the field as well as what the components and assemblies have been exposed to the degree whereby changes in wind velocities and exposure over time with the changing environment will be some of the main causes that result in the joints having various sized gaps, not to mention that the welding is performed out of position as opposed to what goes on in the shop for the most part where the overall conditions are soooooo much better to fabricate, weld and repair...
The bottom line is that when you're in the field, you must consider much more of the environment you're working which in itself will slow down production when compared to what can be produced in a relatively stable environment such as in the shop so you cannot plan the work as you would in the shop...
If I were in your shoes and was thinking of pursuing this job, I would first go over all of the area's of the tower on the print with the contractor and the EOR to educate them as to why they cannot expect you to perform the work in the same manner and with the same speed as one would witness or perform in shop conditions... And simultaneously go over the different locations where you already scouted, and know that location A will take approximately this amount of time to complete with the justification as to why, and to leave yourself a little wiggle room for anything unexpected as a cushion... And then continue to go over the same with locations B, C, D, etc. until everybody is on the same page before you even start the job...
If they object to what you propose, then walk away because if they will not listen and take into consideration what you are describing to them based on your own experience then they're not giving you the respect you deserve and should expect as a professional for going into a hostile environment and putting yourself at risk in order to get the job done especially if they don't give any consideration to the serious safety issues involved and the time it takes to implement the necessary mitigating procedures that must be followed in order to finish the job in one piece... Never forget that if they want to compromise your safety so that they could look good with the production schedule while you put yourself in jeopardy then it's just not worth it Shawn!
Respectfully,
Henry